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CO 2 regulations on heavy-duty transport are introduced in essentially all markets within the next decade, in most cases in several phases of increasing stringency. To cope with these mandates, developers of engines and related equipment are aiming to break new ground in the fields of combustion, fuel and hardware technologies. In this work, a novel diesel fuel injector, Delphi's DFI7, is utilized to experimentally investigate and compare the performance of ramped injection rates versus traditional square fueling profiles. The aim is specifically to shift the efficiency and NO x tradeoff to a more favorable position. The design of experiments methodology is used in the tests, along with statistical techniques to analyze the data. Results show that ramped and square rates- A fter optimization of fueling parameters-produce comparable gross indicated efficiencies. Tests were carried out at 1200 and 1425 rpm; for the latter engine speed peak efficiency was attained at considerably lower NO x levels by applying a ramped injection rate. Particulate matter emissions, on the other hand, are generally lower with the use of square profiles. Heat release analysis further reveals that ignition delays in ramped rate operation are quite long, hinting at vastly different spray behavior. The relatively low loads applied in this work only sustain the delays further. Altogether, this causes the potential of the rate shaping capabilities to be underexploited, as direct control over the burn rate is limited with the combustion system used in this work. The results emphasize the need to carefully select ramp slopes for a particular engine geometry, load and speed point, and additional operating parameter settings.

Partially premixed combustion (PPC) is a promising way to achieve high thermal efficiency and low emissions, especially by using multiple injection strategies. The mechanisms behind PPC efficiency are still to be explained and explored. In this paper, multiple injections have been used to affect the gross indicated efficiency in an optical PPC engine modified from a Volvo MD13 heavy-duty diesel engine. The aim is both to improve and impair the gross indicated efficiency to understand the differences. The combustion natural luminosity is captured by a high-speed camera, and the distribution of fuel, oxygen, and temperature during the combustion process has been further explored by CFD simulation. The results show that with the right combination of the pilot, main, and post injection the gross indicated efficiency can be improved. Using a post injection in a triple-injection case show to have less effect on the combustion phasing than pilot injection in a double-injection case, while it can significantly affect combustion efficiency. The later of the double-injection cases tested (c30/16), has less heat transfer losses since the high-temperature region transported away from the cylinder head and piston bowl wall, which can be seen in the CFD-simulations. The highest gross indicated efficiency among the tested cases is given by the triple-injection case d38/24/6 as it reaches the best balance between the mixing and the local temperature through the jet-jet interactions and combustion-jet interactions. (Less)

Due to the prevalent fuel economy, research on electric hybrid vehicles (HEVs) has attracted recently widespread attention. However, most researches were focused on electrification, neglecting the crucial role of internal combustion engines (ICEs) in reducing fuel consumption. Holding the opinion that ICEs can contribute more in developing fuel economic vehicles, we present in this paper a new HEV topology with two ICEs - Dualhybrid. Two separate traction units, conventional drivetrain with ICE1at front axle and electric hybrid drivetrain with ICE2+battery at rear axle constitute the powertrain of this new HEV concept. One dimensional simulation with sub-models built upon different modelling methods is implemented. Energy management of Dualhybrid is identified with a rule-based control strategy. Base and Fullhybrid model were built as references and a comparative simulation among the three models as conducted. On the basis of the simulation results, an analysis of the efficiency of the powertrains was performed in detail. Results show that Dualhybrid equipped with two ICEs is more fuel economic compared to the reference models and has proven to be an effective HEV concept.

The optimal control of hybrid powertrains represents one of the most challenging tasks for the compliance with the legislation concerning CO2 and pollutant emission of vehicles. Most common off-line optimization strategies (Pontryagin minimum principle-PMP-or dynamic programming) allow to identify the optimal control along a predefined driving mission at the expense of a quite relevant computational effort. On-line strategies, suitable for on-vehicle implementation, involve a certain performance degradation depending on their degree of simplification and computational effort. In this work, a simplified control strategy is presented, where the conventional power-split logics, typical of the above-mentioned strategies, is here replaced with an alternative utilization of the thermal and electric units for the vehicle driving (Efficient Thermal Electric Skipping Strategy-ETESS). The choice between the units is realized at each time and is based on the comparison between the effective fuel rate of the thermal engine and an equivalent fuel rate related to the electrical power consumption. The equivalent fuel rate in a pure electric driving is associated to a combination of brake specific fuel consumption of the thermal engine, and electro-mechanical efficiencies along the driveline. The ETESS is applied for the simulation of segment C hybrid vehicle, equipped with a thermal engine and two electric units (motor and generator). The methodology is tested along regulatory driving cycles (WLTP, Artemis) and RDE, with different powertrain variants. Numerical results underline that the proposed approach performs very close to most common control strategies (consumed fuel per kilometer higher than PMP of about 1% on average). The main advantage is a reduced computational effort (decrease of 99% on average). The ETESS is straightforwardly adapted for an on-line implementation, through the introduction of an adaptative factor, preserving the computational effort and the fuel economy.

Driving cycles are typically used for estimation of vehicle fuel/energy consumption and CO2 emissions. In most of applications only the vehicle velocity vs. time profile is considered as a driving cycle, while a road slope is typically omitted. Since the road slope significantly impacts the fuel consumption, it should be included into realistic driving cycles for hilly roads. As a part of wider research of multidimensional driving cycle synthesis, this paper focuses on analysis of a broad city bus driving cycle dataset recorded in the city of Dubrovnik. The analysis is aimed at revealing the impact of road slope on velocity and acceleration distributions, and clustering the recorded data into several groups reflecting various driving and traffic congestion characteristics. Finally, the Markov chain method is employed to synthesize 3D driving cycles for the selected data clusters, where the Markov chain states include vehicle velocity, vehicle acceleration, and road slope. The synthesized cycles are validated to ensure their representativeness in terms of faithful description of main features of the recorded driving cycles.

This paper presents the emissions results and operational behavior of two hybrid vehicles over EU legislative Real Driving Emissions (RDE) and other on-road testing cycles. The behavior of one hybrid vehicle during real world driving is investigated, including analyses of air-fuel ratio and catalyst temperature changes, in order to elucidate the reasons for the emissions results seen in the other hybrid vehicle over an RDE cycle. It was observed that the catalyst cooled down over time when the hybrid vehicle SI (Spark Ignition) engine was turned off, meaning that when the engine restarted the catalyst efficiency was decreased until it was able to light-off once again. This leads to increases in the tailpipe emissions of CO, NOx and hydrocarbons after the engine restarts. In addition to this problem, the engine restarts demanded fuel enrichment, which resulted in incomplete combustion and further increases in CO and PN emissions. Finally, the rate of catalyst temperature decrease during engine-off and increase during engine start/restart were also investigated and quantified for one of the hybrid vehicles.

Optical diagnostic was applied to undiluted engine exhaust to supply a low cost and real time evaluation of the oil dilution tendency of selected fuels. Specifically, UV-visible-near IR extinction spectroscopy was applied in the exhaust line of a Euro 5 turbocharged, water cooled, DI diesel engine, equipped with a common rail injection system. The engine was fuelled with commercial B5 fuel and a B30 v/v blend of RME and ultra low sulfur diesel. The proposed experimental methodology allowed to identify the contribution to the multi-wavelength extinction of soot, fuel vapor, hydrocarbons and nitrogen oxide. Further, the evolution of each species for different post-injection interval settings was followed. On-line optical results were correlated with off-line liquid fuel absorption values. Moreover, spectroscopic measurements were linked to in-cylinder pressure related data and with HC and smoke exhaust emissions. The late post injection activation and fuel amount increase did not affect the energy release within the cylinder for either fuels. As a consequence, soot and NOx exhaust emissions remained constant during the post-injection setting. The HC exhaust increase was correlated to post-injection amount and followed in the time by UV extinction signal. The blend B30 attained a lower UV signal that was related to higher oil dilution tendency of biofuel.

The EU emission standards for new rail Diesel engines are becoming even more stringent. EGR and SCR technologies can both be used to reduce NOx emissions; however, the use of EGR is usually accompanied by an increase in PM emissions and may require a DPF. On the other hand, the use of SCR requires on-board storage of urea. Thus, it is necessary to study these trade-offs in order to understand how these technologies can best be used in rail applications to meet new emission standards. The present study assesses the application of these technologies in Diesel railcars on a quantitative basis using one and three dimensional numerical simulation tools. In particular, the study considers a 560 kW railcar engine with the use of either EGR or SCR based solutions for NOx reduction. The NOx and PM emissions performances are evaluated over the C1 homologation cycle. The simulation results indicate that either EGR or SCR based solutions can be used to achieve Stage IIIB NOx limits for the 560 kW engine, with an acceptable trade-off regarding BSFC in the case of EGR solutions. In the case of EGR, though, a DPF is necessary to meet Stage IIIB PM limits. Furthermore, SCR based solutions have the potential to go beyond the Stage IIIB NOx limit by scaling up the size of the SCR device and the on-board urea storage. Copyright © 2013 SAE International.

International audience

International audience; Increasing the degrees of freedom in the air path has become a popular way to reduce the fuel consumption and pollutant emissions of modern combustion engines. That is why technical definitions will usually contain components such as multi or single-stage turbocharger, throttle, exhaust gas recirculation loops, wastegate, variable valve timing or phasing, etc. One of the biggest challenges is to precisely quantify the gas flows through the engine. They include fresh and burnt gases, with trapping and scavenging phenomena. An accurate prediction of these values leads to an efficient control of the engine air fuel ratio and torque. Fuel consumption and pollutant emissions are then minimized. In this paper, we propose to use an artificial neural networkbased model as a prediction tool for the engine volumetric efficiency. Results are presented for a downsized turbocharged spark-ignited engine, equipped with inlet and outlet variable valve timing. The calibration process that is used in this study only requires steady-state operating points. The validation stage was conducted on both steady-state and vehicle transients. Model prediction is in very good agreement with experimental results while keeping a very low calibration effort and matching embedded computational requirements. The conclusion stresses that thanks to their generic structure, neural models offer an interesting potential for generalization to even more complex technical definitions.

This paper builds upon recent publication (SAE Technical Paper 2011-01-1388, 2011, doi:10.4271/2011-01-1388) and outlines the on-going development of an advanced simulator for virtual engine mapping and optimization of engine performance, combustion and emissions characteristics. The model is further advanced through development of new sub-models for turbulent mixing, multiple injection events, variable injection pressures, engine breathing and gas exchange, as well as particulates formation and oxidation. The result is a simulator which offers engine design and performance data typically associated with 1D thermodynamic engine cycle simulations but with the “physics-based” model robustness usually associated with 3D CFD methods. This combination then enables efficient optimization of engine design with respect to engine performance, combustion characteristics and exhaust gas emissions. As a demonstration, a detailed method to parameterize (calibrate) the advanced PDF-based model is presented followed by application to three case studies: 1) a concept study of a heavy duty diesel engine, examining the impact of increased injection pressure and lower compression ratio to meet engine design constraints and Stage IV/Tier 4 exhaust gas emission limits for both NOx and PM, 2) examining the performance of both the proposed model and 3D-CFD to simulate heat release and exhaust gas emissions in a HSDI diesel engine, 3) performance of the model over a full loadspeed map in terms of combustion and NOx emissions. The results demonstrate the robustness of the model compared to experimental observations and equivalent performance compared to more human resource and CPU cost intensive 3D-CFD simulations.

We present an optimal control solution for the urea injection for a heavy-duty diesel (HDD) selective catalytic reduction (SCR). The approach taken here is useful beyond SCR and could be applied to any system where a control strategy is desired and input-output data is available. For example, the strategy could also be used for the diesel oxidation catalyst (DOC) system. In this paper, we identify and validate a one-step ahead Kalman state-space estimator for downstream NOx using the bench reactor data of an SCR core sample. The test data was acquired using a 2010 Cummins 6.7L ISB production engine with a 2010 Cummins production aftertreatment system. We used a surrogate HDD federal test procedure (FTP), developed at Michigan Technological University (MTU), which simulates the representative transients of the standard FTP cycle, but has less engine speed/load points. The identified state-space model is then used to develop a tunable cost function that simultaneously minimizes NOx emissions and urea usage. The cost function is quadratic and univariate, thus the minimum can be computed analytically. We show the performance of the closed-loop controller in using a reduced-order discrete SCR simulator developed at MTU. Our experiments with the surrogate HDD-FTP data show that themore » strategy developed in this paper can be used to identify performance bounds for urea dose controllers.« less

Nowadays, alcoholic fuels gain increased interest as alternative transportation biofuel even in compression ignition engines due to the fact that they contain oxygen and can be produced in a sustainable way. Furthermore, due to their lower CN (Cetane Number) they suit better for premixed combustion applications. Experimental research was conducted on a single cylinder engine provided with modern engine architecture modified for DF (Dual-Fuel) purposes. The authors have investigated the use of ethanol in a DF engine in order to exploit its well-known advantages in premixed combustion mode. The DF approach appears to be a promising solution because it permits flexible control of the premixed fuel fraction regardless from the operating conditions. This improves the exploitation of the ethanol potential according the engine working conditions. Recent literature publications have proved the possibility to increase the thermodynamic efficiency at medium and high load in DF configuration compared to a conventional DI (Direct Injection) diesel configuration. However, it is still not clear what the effective working area and right control parameters for light duty engines are for which the DF configuration outperforms the DI diesel configuration. Within this framework, the research was performed to provide additional knowledge on DF in terms of operating range and engine control strategies (e.g. injection parameters). At medium and high load, the results show the potential for ethanol to decrease NOx and soot emissions simultaneously while improving the thermal efficiency. On the contrary, a significant increase of HC (Hydro Carbon) and CO (Carbon Monoxide) emissions were observed for low load and the DI diesel configuration outperformed the DF configuration in terms of emissions and efficiencies.

Multi-wavelength ultraviolet-visible extinction spectroscopy was applied to follow the evolution of fuel vapor injected by post-injection along the exhaust line of a common-rail turbocharged direct-injection diesel engine at moderate speed and load. The exhaust line was specifically designed and customized to allow the insertion of the optical access upstream of the Diesel Oxidation Catalyst. During the experimental campaign, the engine was fuelled with commercial B5 fuel and a B30 v/v blend of RME and ultra low sulfur diesel, monitoring emissions upstream of the catalyst and exhaust gas temperature across the catalyst. Tests were performed at different engine operating conditions with particular attention to moderate speed and load. The high temporal evolution of the UV-visible extinction measurements allowed to follow the evolution of the fuel vapor injected by post-injection during the transition from standard combustion mode to filter regeneration combustion mode, characterized by a higher amount of fuel injected into the exhaust line. Results indicate that, in some engine operating conditions, the fuel vapor formed by post-injection does not completely contribute to the oxidation process over the catalyst since a negligible increase in temperature has been recorded across the catalyst.

In the truck industry there is a continuous demand to increase the efficiency and to decrease the emissions. To acknowledge both these issues a waste heat recovery system (WHR) is combined with a partially premixed combustion (PPC) engine to deliver an efficient engine system. Over the past decades numerous attempts to increase the thermal efficiency of the diesel engine has been made. One such attempt is the PPC concept that has demonstrated potential for substantially increased thermal efficiency combined with much reduced emission levels. So far most work on increasing engine efficiency has been focused on improving the thermal efficiency of the engine while WHR, which has an excellent potential for another 1-5 % fuel consumption reduction, has not been researched that much yet. In this paper a WHR system using a Rankine cycle has been developed in a modeling environment using IPSEpro. A comparative investigation of the WHR potential between the existing conventional diesel combustion and the novel PPC combustion is done. Even though the PPC is a low temperature combustion concept (LTC), implying that the exhaust temperatures are lower than for the traditional diesel combustion, the EGR quantity is higher which in total still offers improved WHR potential as that of conventional combustion. The EGR cooler offers higher quality heat when compared to exhaust gas and CAC, hence the WHR potential using only the EGR system is considered in this paper.

The information provided by the in-cylinder pressure signal is of great importance for modern engine management systems. The obtained information is implemented to improve the control and diagnostics of the combustion process in order to meet the stringent emission regulations and to improve vehicle reliability and drivability. The work presented in this paper covers the experimental study and proposes a comprehensive and practical solution for the estimation of the in-cylinder pressure from the crankshaft speed fluctuation. Also, the paper emphasizes the feasibility and practicality aspects of the estimation techniques, for the real-time online application. In this study an engine dynamics model based estimation method is proposed. A discrete-time transformed form of a rigid-body crankshaft dynamics model is constructed based on the kinetic energy theorem, as the basis expression for total torque estimation. The major difficulties, including load torque estimation and separation of pressure profile from adjacent-firing cylinders, are addressed in this work and solutions to each problem are given respectively. The experimental results conducted on a multi-cylinder diesel engine have shown that the proposed method successfully estimate a more accurate cylinder pressure over a wider range of crankshaft angles. Copyright © 2012 SAE International.

The most common car engine is a 4-cylinder 4-stroke engine. The car manufacturers have a great pressure to lower the cost of the cars and this deal also with the engines. The challenges are the coming new emission norms (for example EURO-6) and also the customer acceptance, because of the fact, that the car drives are used to the 4-cylinder engine and they want to have the same driving fun also from the new engines. A 2-cylinder 2-stroke engine has the same power output and torque as a 4-cylinder 4-stroke engine and thus it offers the same driving fun. Equal balancing is easy to make without some big additional costs, if the gas exchange of the engine is made by using poppet valves and camshafts. As there are only about 70% of the moving parts in the engine, its acceleration is even better than by a 4-cylinder engine. One of the latest development in 2-stoke engines is the Z-engine (1), having the compression partially transferred outside of the working cylinders. This offers new thermo dynamical possibilities to adjust the working cycle and the combustion. As there are methods to control the temperature at TDC, a HCCI-combustion is possible in the Z-engine at all loads. This lowers significantly the cost of the engine, as no urea injection, or NOx catalyst is needed to pass the coming EU-6 emission norm. The cost of the Z-engine is lower also because of the fact that it has only 2 working cylinders instead of 4. In 1999, Aumet Oy (73) began to research this 2-stroke car diesel engine, called the Z-engine, in co-operation with the Internal Combustion Engine Laboratory at the Helsinki University of Technology (HUT) and the Energy Technology Department at the Lappeenranta University of Technology (LUT). So far, four master’s theses, one doctor theses, five SAE Papers (71, 72) and four Fisita Papers have been completed on the subject. Modern simulation tools, such as Star CD, GT-Power, Diesel RK, Fluent and Chemkin have been used. The prototype engine made its start in December 2004 and it was tested two years in a test bench at VTT. In the HCCI combustion simulation of the Z-engine, a 4-dimensional ignition delay map, calculated with Chemkin and integrated in Diesel RK (74), has been used. The simulations and tests (1) with the test engine show that the Z-engine has a very good efficiency, especially at part load. A diesel fuel HCCI-combustion at all loads is possible in the Z-engine, with lambda about 1,5-1,7 and EGRrate 15-45%, depending of the load. The TDC-temperature at part load is about 800 K and at full load (BMEP 30 bar) about 700 K. The HCCI-ignition, triggered with a small amount of diesel fuel injection close to TDC (RCCI, based on the reactivity difference on lambda of the two air-fuel mixtures in the cylinder: early injected and ignition injection), occurs between 0°20° ATDC and this limits the pressure and maximal temperature. No knock is present, as the ignition occurs always at the right side of the NTC (negative temperature coefficient) regime (30,31). NOx values are very low as the maximal temperature at full load is about 1900 K, because of the low starting temperature of the combustion, intern EGR and the expansion during the combustion. Intern EGR and active radicals stabilize the combustion (32-37) and lower the activation energy needed for the ignition. The robust HCCI-combustion without ignition problems (forced ignition, very early diesel fuel injection and thus active radicals) has been validated with 2-stroke test engines in Dr. Zhengs Doctor Theses together with his research colleges in Drexel University, Philadelphia, USA, 2005, (36). The fuel consumption is: part load 192 g/kWh, best point 174 g/kWh and full load 188 g/kWh. The part load efficiency is much better than by PCI and dual fuel RCCI, best point and full load values are of the same order. The explanation for the very good part load efficiency is the exergy increase , when the intercooled, compressed air is led in to the work cylinder and mixed with the hot, almost atmospheric combustion gases , having high intern energy, but almost zero exergy. The pressure increase at the end of the gas exchange increases also the efficiency. This is easy to understand, when seeing the gas exchange simulations, made with CFD, Appendix 2. The very short time in the gas exchange of the Z-engine, about one millisecond, makes the need of the understanding of the gas dynamics very important. The acceleration of the gas in the intake channel, as much as 50000G and the high velocity leads to high pressure rise at the end of the gas exchange, at full load up to 10 bar ( Appendix 2). This is not the case with normal engines. This very unique combination of thermodynamic and gas dynamic, first time in the history of the combustion engines, makes it possible to start the work cycle, as already Diesel wanted: isotherm and isentropic compressions, according to Carnot (see in TS). The

For Homogeneous Charge Compression Ignition (HCCI) combustion, the auto-ignition process is very sensitive to in-cylinder conditions. This includes the change in in-cylinder temperature, the composition of chemical components and their concentrations. This sensitivity presents a major challenge for the accurate control of reliable and efficient HCCI combustion. This paper outlines our recent work: 1. a real-time control oriented gasoline-fueled HCCI combustion model and its implementation in Simulink with fixed step for the conversion into dSPACE Hardware-in-the-Loop (HIL) simulation purpose. 2. The development of model-based fast calibration for the best fuel efficiency and hydrocarbon emissions via evolutionary algorithm (EA). The model reported in this paper is able to run in real-time cycle-to-cycle under engine speeds below 4000rpm and with fixed simulation steps. This aims to achieve cycle-to-cycle performance calculation for Model based Predictive Control (MPC) and HIL simulation. With the aim of controlling the desired amount of trapped Exhaust Gas Recirculation (EGR) from the previous cycle, the phase of the Intake Valves Opening (IVO) and Exhaust Valves Closing (EVC) are designed to vary in this model. The model is able to anticipate the auto-ignition timing, MFB, combustion duration, in-cylinder pressure and hydrocarbon emissions etc. The validation has been conducted by comparing experimental data obtained from a Jaguar HCCI/SI V6 GDI engine at the University of Birmingham. This comparison shows good agreement between the simulation results and experimental data. Copyright © 2012 SAE International.

The aerospace manufacturing sector is continuously seeking automation due to increased demand for the next generation single-isle aircraft. In order to reduce weight and fuel consumption aircraft manufacturers have increasingly started to use more composites as part of the structure. The manufacture and assembly of composites poses different constraints and challenges compared to the more traditional aircraft build consisting of metal components. In order to overcome these problems and to achieve the desired production rate existing manufacturing technologies have to be improved. New technologies and build concepts have to be developed in order to achieve the rate and ramp up of production and cost saving. This paper investigates how to achieve the rib hole key characteristic (KC) in a composite wing box assembly process. When the rib hole KC is out of tolerances, possibly, the KC can be achieved by imposing it by means of adjustable tooling and fixturing elements. A test rig has been designed and built that is used to experimentally investigate the capability of both the tooling and fixturing concepts. Some experiments have been carried out that successfully demonstrate the capability of the reconfigurable fixturing technology to achieve the rib hole KC.

The introduction of advanced internal combustion engine mechanisms and powertrains may improve the fuel conversion efficiency of an engine and thus reduce the amount of energy needed to power the vehicle. The paper presents a novel design of a variable compression ratio advanced spark ignition engine that also permits an expansion ratio that may differ from the induction stroke therefore generating an Atkinson cycle effect. The stroke ratio and the ratio of maximum to minimum in-cylinder volumes may change with load and speed to provide the best fuel conversion efficiency. The variable ratio of maximum to minimum in-cylinder volumes also improves the full load power output of the engine. Results of vehicle driving cycle simulations of a light duty gasoline vehicle with the advanced engine show dramatic improvements of fuel economy. The novel gasoline vehicle has close to diesel fuel energy usage and CO2 production while retaining the after treatment advantages of the stoichiometric operation with spark ignition. Coupled to advanced powertrains using mechanical kinetic energy recovery systems to recover the braking energy thus reducing the thermal energy supply in the following acceleration phase, these engines may offer even better than current hybrid electric vehicles fuel economy (comparison of compact size passenger cars with a turbo direct injection diesel and a mechanical kinetic energy recovery system and a gasoline hybrid electric vehicle published in a previous paper). The results of the paper are based on modelling techniques. These results need to be confirmed by experiments.

Premixed combustion modes in compression ignition engines are studied as a promising solution to meet fuel economy and increasingly stringent emissions regulations. Nevertheless, PCCI combustion systems are not yet consolidated enough for practical applications. The high complexity of such combustion systems in terms of both air-fuel charge preparation and combustion process control requires the employment of robust and reliable numerical tools to provide adequate comprehension of the phenomena. Object of this work is the development and validation of suitable models to evaluate the effects of charge premixing levels in Diesel combustion. This activity was performed using the Lib-ICE code, which is a set of applications and libraries for IC engine simulations developed using the OpenFOAM® technology. In particular, a turbulence-chemistry interaction model, based on the simple Eddy Dissipation Approach, was introduced to account for the effects of turbulent mixing on chemical reaction rates. It is a tentative solution to represent the effects of sub-grid mixing on the chemical reaction rates when detailed reaction mechanisms are adopted. Chemical reaction rates were computed by a robust semi-implicit extrapolation method for integrating stiff Ordinary Differential Equations with monitoring of both local and global error to adjust stepsize. To reduce the CPU time when detailed chemistry was used, both the ISAT (in-situ adaptive tabulation) and DAC (dynamic adaptive chemistry) techniques were adopted in combination. Simulations were performed by varying the charge premixing level from the typical diesel combustion mode towards an almost completely premixed/HCCI mode using n-heptane, whose injected mass was split between portinjection and direct-injection. This allowed a detailed investigation of the “mixed injection conditions”, that are typical of dual fuel configurations without employing fuels of different chemical nature, composition and ignition tendency. The choice of using a single fuel was motivated by the need to isolate the effects of different premixing levels and the resulting interaction between the charge and the fuel spray. Measurements for validation were collected by means of specific experiments on a fully instrumented single cylinder research engine, having the injection and the combustion systems architecture typical of the current light duty diesel engine technology. To realize homogeneous air-fuel charge, the intake manifold is modified to provide the desired extent of fuel port-injection.

The goal of this paper is to acquire insight into the influence of cetane number (CN) and fuel oxygen on overall engine performance in the Premixed Charge Compression Ignition (PCCI) combustion mode. From literature, it is known that low reactive (i.e. low CN) fuels increase the ignition delay (ID) and therefore the degree of mixing prior to auto-ignition. With respect to fuel oxygen, it is known that this has a favorable impact on soot emissions by means of carbon sequestration. This makes the use of low CN oxygen fuels an interesting route to improve the applicability of PCCI combustion in diesel engines. In earlier studies, performed on a heavy-duty engine, cyclic oxygenates were found to consistently outperform their straight and branched counterparts with respect to curbing soot. This was attributed to a considerably lower CN. The oxygenate in question, cyclohexanone (C6H10O), has the advantage of being producible in a renewable way from lignin, a second generation biomass waste stream (e.g. paper pulp industry). To investigate the impact of cyclohexanone on diesel combustion and pollutant emissions in greater detail, a parametric test program was carried out in a joint project between Istituto Motori (Naples) and the University of Technology Eindhoven. To decouple the influence of a low cetane number and fuel oxygen content on the engine performance, diesel (commercial high quality diesel fuel), gasoline (commercial high quality gasoline) and cyclohexanone were blended into five mixtures, with varying cetane number or oxygen content. These blends were tested and compared on a modern singlecylinder light-duty (LD) direct injection (DI) research diesel engine. The results suggest that it is not possible to attribute favorable performance to either CN or fuel oxygen, but rather to the combination of both properties. In nearly all investigated work points, a decrease in CN led to a decrease in nitric oxides (NOx) and particulate matter (PM), whilst slightly increasing carbon monoxide (CO) and unburned hydrocarbons (UHC). At an equal CN, the results suggest that fuel oxygen reduces soot emissions and also plays a role in suppressing UHC and CO emissions.

This paper shows the main results of a research activity carried out in order to investigate the impact of different hybridization concepts on vehicle fuel economy during standard homologation cycles (NEDC, FTP75, US Highway, Artemis). Comparative analysis between a standard passenger vehicle and three different hybrid solutions based on the same vehicle platform is presented. The following parallel hybrid powertrain solutions were investigated: Hybrid Electric Vehicle (HEV) solution (three different levels of hybridization are investigated with respect to different Electric Motor Generator size and battery storage/power capacity), High Speed Flywheel (HSF) system described as a fully integrated mechanical (kinetic) hybrid solution based on the quite innovative approach, and hydraulic hybrid system (HHV). In order to perform a fare analysis between different hybrid systems, analysis is also carried out for equal system storage capacities. All hybrid powertrain architectures include state-of-the-art hybrid components and are analyzed from the aspects of fuel economy related to the overall system efficiency, load point moving of the internal combustion engine due to energy flow control strategy operation, and regenerative braking (applying realistic drivability constraints). The simulations were performed within the IAV-VeLoDyn software environment. VeLoDyn (Vehicle Longitudinal Dynamics Simulation) is a modular and highly flexible Simulink-based software tool, which offers a straightforward simulation of longitudinal vehicle dynamics with special considerations on the driveline and model management functionality. In order to provide control and management of the hybrid powertrain system, a cycleindependent control strategy has been implemented into the supervisory hybrid control unit model, based on Equivalent Consumption Minimization Strategy (ECMS) approach. Due to the modular nature of the simulation tool, the control strategy was effectively implemented in all analyzed hybrid models with marginal modifications. In order to determine energy flows and validate hybrid powertrain behavior, a cycle-based energetic analysis was carried out, and the main results are presented in the paper.

Ice buildup in the compressor section of a commercial aircraft gas turbine engine can cause a number of engine failures. One of these failure modes is known as engine rollback: an uncommanded decrease in thrust accompanied by a decrease in fan speed and an increase in turbine temperature. This paper describes the development of a model which simulates the system level impact of engine icing using the Commercial Modular Aero-Propulsion System Simulation 40k (C-MAPSS40k). When an ice blockage is added to C-MAPSS40k, the control system responds in a manner similar to that of an actual engine, and, in cases with severe blockage, an engine rollback is observed. Using this capability to simulate engine rollback, a proof-of-concept detection scheme is developed and tested using only typical engine sensors. This paper concludes that the engine control system s limit protection is the proximate cause of iced engine rollback and that the controller can detect the buildup of ice particles in the compressor section. This work serves as a feasibility study for continued research into the detection and mitigation of engine rollback using the propulsion control system.

The paper presents the development and real-time implementation of a combustion control system based on optimal management of multiple spark discharge events, in order to increase combustion stability, reduce pollutant emissions and fuel consumption, and avoid partial or missing combustion cycles. The proposed approach has been developed as a costeffective solution to several combustion-related issues that affect Gasoline Direct Injection (GDI) engines during cold start and part load operation. The problem of optimizing combustion efficiency and improving its stability during such operating modes is even more critical for high performance engines, which are designed to maximize charge efficiency especially at medium-high engine speeds. The main benefits that have been achieved by introducing and optimizing a multi-spark ignition mode can be summarized as follows: missing and partial burn combustions elimination, combustion variability minimization, HC emissions reduction (also due to absence of misfiring events), NOx emissions reduction (mainly due to the possibility of increasing residual gas fraction), significant specific fuel consumption reduction (especially during very low load operation - brake mean effective pressure around 0.5∼1.0 bar - and during cold start operation). Finally, the paper introduces the idea of extracting from ion current signals information related to combustion instability, which can be used to activate multi-spark mode, and to identify the optimal charge-discharge sequential pattern. The main characteristics of the rapid control prototyping system that has been developed to demonstrate the feasibility and the effectiveness of the proposed solution are synthesized in the first part of the paper, while the multi-spark pattern calibration process and the main experimental results are shown next, both during test cell and on-board operation.

Over the past couple of years, numerous Hybrid Electric Vehicle (HEV) powertrain configurations have been introduced into the marketplace. Currently, the dominant architecture is the power-split configuration, notably the input splits from Toyota Motor Sales and Ford Motor Company. This paper compares two vehicle-level control strategies that have been developed to minimize fuel consumption while maintaining acceptable performance and drive quality. The first control is rules based and was developed on the basis of test data from the Toyota Prius as provided by Argonne National Laboratory’s (Argonne’s) Advanced Powertrain Research Facility. The second control is based on an instantaneous optimization developed to minimize the system losses at every sample time. This paper describes the algorithms of each control and compares vehicle fuel economy (FE) on several drive cycles. Results demonstrate that both algorithms achieve similar FE values, which serve to demonstrate the benefits of the instantaneous optimal control: because it does not require tuning by the engineers, control development time is accelerated.

Helsinki Region Transport, Neste Oil, Proventia Emission Control and VTT Technical Research Centre of Finland carried out a 3.5 year PPP venture "OPTIBIO" to demonstrate the use of paraffinic renewable diesel (hydrotreated vegetable oil HVO) in city buses. The fleet test in Metropolitan Helsinki involving some 300 buses is the largest one in the world to demonstrate this new fuel. The fuels were a 30 % blend of renewable diesel and 100 % renewable diesel. This paper describes the overall set-up of the project, gives an overview of the emission results as well as presents experience from the field.

Nowadays an elevated number of two, three and four wheels vehicles circulating in the world-wide urban areas is equipped with Port Fuel Injection Spark Ignition (PFI SI) engines. Their technological level is high, but a further optimization is still possible, especially at low engine speed and high load. To this purpose, the scientific community is now focused on deepening the understanding of thermo fluid dynamic phenomena that takes place in this kind of engine: the final purpose is to find key points for the reduction in engine specific fuel consumption and exhaust emissions without a decrease in performance. In this work, the combustion process was investigated in an optically accessible single cylinder PFI SI engine. It was equipped with the head, injection device and exhaust line of a commercial small engine for two-wheel vehicles, it had the same geometrical characteristics in terms of bore, stroke and compression ratio. The combustion chamber was optically accessible through a quartz ring under the engine head and a sapphire window on the piston top. Cycle-resolved visualization was carried out to follow the flame propagation from the spark ignition until the late combustion phase. The visualization was performed from the bottom of the engine and from the lateral side with different camera inclinations. High spatial resolution visualization of the combustion process was carried out. Moreover two color pyrometry method was applied to evaluate the spatial distribution of diffusion flames temperature and soot concentration in the combustion chamber. UV-visible emission spectroscopy was used to identify the chemical species that feature the combustion process and to study the pollutants formation. The cyclic variability and the fuel deposits formation on the combustion chamber surfaces were also investigated. All the measurements carried out in the combustion chamber were correlated with the main engine parameters and exhaust emissions. The effect of the fuel injection phasing was tested. Two fuel injection strategies were considered: in the first one, the fuel injection started when the intake valves were open; in the second one the fuel injection occurred at closed intake valves.

A new design of integrated Electric Parking Brake system, called iEPB and integrated in the brake caliper, is introduced in this paper. It consists of an electrically operated brake unit and a hydraulically pressed unit independently, and uses a special self-locking mechanism instead of a screw device to increase the efficiency and the working speed. With all conventional EPB system’s advantages, it also provides a stronger brake performance and a faster reaction time. In this paper, we describe the working principle of this new design at first, and then introduce the arrangement of the testing system, followed by a discussion of experimental data. The testing results prove the feasibility of this design. The conclusion paragraph summarizes the key points about the design of the iEPB system. INTRODUCTION The iEPB system is more convenient and safety than traditional parking systems. It’s operated and released automatically. With integrated intelligent function, the iEPB system has the following merits: • Replace a hand lever by an operation button. • Because of no hand lever, there is more space in the vehicle. • Combining a control unit, the iEPB system can be automatically operated and released at the right time, which makes the operation simpler and the driver to feel more comfortable and safer. • With high performance mechanism, the iEPB system has a faster reaction time. So we can provide the Auto-Hold function by adopting the iEPB system. There are two types of existing electric parking brake. One type is the cable puller[3], and the other is the integrated caliper[4]. This new design belongs to the integrated caliper type. Almost 100% integrated caliper type of market products use the screw device as its linear mechanism. The screw device can provide a large reduction ratio in a small space and transfer the rotation motion into linear motion with a non-reverse feature. But a low mechanical efficiency due to the screw friction makes a great energy lose. In this paper, we introduce a new design that is a type of screw free concept. Basing on the same power source, the screw free design can reduce about three-quarter reaction time of the system [5]. SYSTEM DESCRIPTION For improving working speed, enhancing mechanism efficiency and providing a non-reverse feature at the same time, the iEPB mechanism design is the key point. The important factors that need to be considered include: • Caliper pressing force. • Working time of the actuator. • Power consumption. • Parking force that can be maintained when power off. Actuator parts The iEPB system working flow diagram is shown in Figure 1, and the illustration of actuator is shown in Figure 2. The iEPB system is comprised of a brush DC motor, a special self-locking mechanism and multi stage reduction gears. The output torque rotates a cam shaft built in the caliper and pushes brake lining to against brake disk for parking purpose, shown in Figure 3. There is no additional friction lose because of the screw free mechanism. The prototype picture is shown in figure 4. Motor Self-locking mechanism Reduction gear Caliper cam shaft Cam Lining shoe Parking Figure 1. iEPB system working flow diagram. Reduction Gear Self-locking mechanism

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The ideal attributes of light weight, low cost and high power density have made the 2-stroke engine unrivalled in the scooter and moped market for many years. However, the challenges of meeting new emissions regulations, especially the latest Euro III emission test cycle have reduced the 2-stroke's dominance and it is now often considered to be too dirty and inefficient to have a future. As a result its product placement is on the decline. This paper introduces and discusses the latest application of a low-cost high-frequency injection system (Pulse Count Injection [1,2]) to both the fuel flow and lubrication oil flow of a 2-stroke scooter; allowing both fluids to be individually mapped and optimised for the complete engine operating range. This in turn enables the 2-stroke engine to pass the latest Euro III test whilst improving the fuel economy by a considerable margin, without changing the architecture of the engine. Examples of the latest developments of a highly integrated engine management system, including fuel and oil injector technology are shown. The paper draws conclusions from the test results showing the clear benefits of electronic fuel injection both for emissions and fuel consumption, and demonstrates that these benefits are achievable from a compact well integrated throttle body unit suitable for the small 2-stroke engine market. INTRODUCTION: 2-STROKE MOTOR APPLICATIONS, CONCERNS AND FUTURE POSSIBILITIES Although the 4-stroke engine has replaced 2-stroke engines in markets where emission legislation has been brought in force, there are still many applications where the light weight and low cost benefits of the 2-stroke engines are so significant as to make them irreplaceable. The lower powered, heavier and more costly 4-stroke engine replacement would severely compromise the function and/or performance of the end product. Examples Page 2 of 14 of these applications are the chainsaw, small outboard motor and limited capacity 'moped' or scooter, where maximum power from a very small, lightweight and low cost engine is paramount. Examples are shown in Figure 1. Figure 1 Examples of applications requiring the lightweight power of a 2-stroke engine However, even in these specialised areas there is a necessity to meet new clean emission standards and reduce fuel consumption (CO2 emissions) in line with environmental trends. It is therefore essential that full electronic control of the 2-stroke engine is applied in order to fully optimise the combustion and performance of these small engines and ensure compliance with future standards. Table 1 shows the historic emissions regulation limits for 2-stroke mopeds and the proposed new limits coming into force in 2012. Table 1 Emission limit trend for 50cc mopeds. Stages Emission limits for type approval and conformity of production for Mopeds Test cycle CO (g/km) HC + NOx (g/km) 1999 (EURO 1) 6.0 3.0 UN-ECE Reg.47 2002 (EURO 2) 1.0 1.2 UN-ECE Reg.47 2012 (EURO 3) 1.0 1.2 UN-ECE Reg.47 Hot and Cold Cycles Previous work has been done showing the dramatic reduction in emissions that can be achieved with 2-stroke engines using "Direct Injection" of the fuel into the combustion chamber [3,4,5] and this technology is often applied to high end expensive 2-stroke engines such as high performance outboard motors and jet skis. However, this solution while technically applicable to the smaller engines carries with it a high on-cost and complexity which has prevented it from large scale application in the low cost markets.

Two of the most pressing challenges of the automotive sector are reduction of fuel consumption and corresponding emission of greenhouse gases, especially when taking into account the growing degree of luxury in modern passenger cars, which increases the auxiliary load on the engine. Preferably, this increase in auxiliary load is compensated by the recovery of waste energy. To accomplish this, a technology called WEDACS (Waste Energy Driven Air Conditioning System) is being developed to recover throttling losses. WEDACS uses a turbine to induce provide the engine with the same air mass flow rate as a throttle valve while producing mechanical energy and cold air. An alternator coupled to this turbine converts mechanical energy into electrical energy and the cold air is used to cool A/C fluid. This way the load of both the engine-mounted alternator and A/C compressor is reduced or eliminated, resulting in higher efficiency. A previous paper provides a proof of principle, using a turbine from a turbocharger, but also discusses a challenge in the form of a limited operating range. The present paper focuses on addressing this challenge. To expand the control range of the engine, a turbocharger with variable nozzle turbine is used. Due to limitations in the variable nozzle mechanism, the range is limited to higher engine powers. It is shown that between 50 W and 1.3 kW of energy can be recovered from a 2-liter engine, depending on the operating point. A second turbocharger's variable nozzle mechanism is adapted to enable control of a 2-liter engine from idle to about 50% engine power. With decreasing engine power, the energy recovery efficiency eventually drops to zero. The root cause for this is identified and an attempt is made to improve efficiency. Finally the drive cycle model from the previous paper is expanded and a new drive cycle simulation shows a fuel consumption improvement over the NEDC of about 5 to 8% for a mid-sized passenger car with a 2-liter engine.

As it is well known one of the most harmful emissions in SI engines is NOx and there are several ways to minimize NOx emission. Internal exhaust gas recirculation (IGR) is an effective way to control and minimize NOx concentration in exhaust gas. In this paper, a method for minimizing NOx emission by use of IGR and variable valve timing (VVT) is introduced. In this method, formation of NOx is controlled by mass fraction of residual gas (RG) and mass fraction of RG is controlled by variable timing of exhaust valves opening and closing so not only the timing of exhaust valves changes but also the lift profile of exhaust valves is variable. In this paper, first a thermodynamic model of a SI engine was developed and validated by experimental data. The model was a reliable tool for predicting engine performance and emission characteristics. The effect of variable exhaust valve timing on RG mass fraction, NOx formation and brake specific fuel consumption was investigated. Then a multi-objective genetic algorithm (NSGA II) was applied to find the optimum timing and lift duration of exhaust valve.

In the study presented in this paper, a vehicle driving cycle simulation of the pneumatic hybrid has been conducted. The pneumatic hybrid powertrain has been modeled in GT-Power and validated against experimental data. The GT-Power engine model has been linked with a MATLAB/simulink vehicle model. The engine in question is a single-cylinder Scania D12 diesel engine, which has been converted to work as a pneumatic hybrid. The base engine model, provided by Scania, is made in GT-power and it is based on the same engine configuration as the one used in real engine testing. During pneumatic hybrid operation the engine can be used as a 2-stroke compressor for generation of compressed air during vehicle deceleration and during vehicle acceleration the engine can be operated as a 2-stroke air-motor driven by the previously stored pressurized air. There is also a possibility to use the stored pressurized air in order to supercharge the engine when there is a need for high torque, like for instance at take off after a standstill or during a overtake maneuver. Previous experimental studies have shown that the pneumatic hybrid is a promising concept with great possibility for fuel consumption reduction during city-driving conditions. Earlier studies have shown a great reduction in fuel consumption whit the pneumatic hybrid compared to conventional vehicles of today. However, most of these studies have been completely of theoretical nature. In this paper, the engine model is based on and verified against experimental data, and therefore more realistic results can be expected. The intent with the vehicle driving cycle simulation is to investigate the potential of the pneumatic hybrid regarding reduction in fuel consumption (FC) compared to a traditional internal combustion engine (ICE) powered vehicle. The results show that a reduction in fuel economy of up to about 30% is possible for a pneumatic hybrid bus on the Braunschweig duty cycle. The main part of this reduction comes from the stop/start functionality of the system, while regenerative braking only contributes with 8.4 % to the reduction in FC. The results also show that an amazing 87% of the braking power can be absorbed and converted to compressed air. However, only a small portion of this energy, about 20%, can be converted to positive work. (Less)

SAE paper 2010-01-0605, Copyright © 2010 SAE International. This paper is posted on this site with permission from SAE International, and is for viewing only. Further use and distribution of this paper is not permitted without permission from SAE. Over the last decade, the diesel engine has made dramatic progress in its performance and market penetration. However, in order to meet future emissions legislations, Nitrogen Oxides (NOx) and particulate matters’ (PM) emissions will need to be reduced simultaneously. Nowadays researchers are focused on different combustion modes which can have a great potential for both low soot and low NOx. In order to achieve this, different injection strategies have been investigated. This study investigates the effects of split injection strategies with high levels of Exhaust Gas Recirculation (EGR) on combustion performance and emissions in a single cylinder direct injection optical diesel engine. The investigation is focused on the effects of injection timing of split injection strategies. A Ricardo Hydra single cylinder optical engine was used in which conventional experimental methods like cylinder pressure data, heat release analysis and exhaust emissions analysis were applied. Optical techniques like direct spray and combustion visualization were applied by means of a high speed imaging system with a copper vapor laser illumination system and a high-speed two-color system was applied to obtain in-cylinder diesel combustion temperature and soot measurements distributions.

Materials Noise, Vibration and Harshness Parts and Components Power and Propulsion Quality, Reliability and Durability Safety Tests and Testing Transportation Systems Vehicles and Performance Other Options Papers by Event SAE Home > Papers> By Event> SAE 2010 World Congress & Exhibition Model Predictive Control of a Combined EGR/SCR HD Diesel Engine Date Published: 2010-04-12Paper Number: 2010-01-1175 DOI: 10.4271/2010-01-1175 Author(s): Claes Westerlund - Scania CV AB Bjorn Westerberg - Scania CV AB Ingemar Odenbrand - Lund Univ. Rolf Egnell - Lund Univ. View All CollapseAbstract Achieving upcoming HD emissions legislation, Euro VI / EPA 10, is a challenge for all engine manufacturers. A likely solution to meet the NO x limit is to use a combination of EGR and SCR. Combining these two technologies poses new challenges and possibilities when it comes to optimization and calibration.

In the study presented in this paper, experimental data from a pneumatic hybrid has been compared to the results from a simulation of the engine in GT-Power. The engine in question is a single-cylinder Scania D12 diesel engine, which has been converted to work as a pneumatic hybrid. The base engine model, provided by Scania, is made in GT-Power and it is based on the same engine configuration as the one used during real engine testing. During pneumatic hybrid operation the engine can be used as a 2-stroke compressor for generation of compressed air during vehicle deceleration and during vehicle acceleration the engine can be operated as a 2-stroke air-motor driven by the previously stored pressurized air. There is also a possibility to use the stored pressurized air in order to supercharge the engine when there is a need for high torque, like for instance at take off after a standstill or during an overtake maneuver. Previous experimental studies have shown that the pneumatic hybrid is a promising concept and a possible competitor to the electric hybrid. This paper consists mainly of two parts. The first one describes an attempt to recreate the real engine as a computer model with the aid of the engine simulation software GT-power. A model has been created and the results have been validated against real engine data. The second part describes a parametric study where different parameters and their effect on pneumatic hybrid performance have been investigated.

The present paper is about the rotational speed measurement of an automotive turbocharger, obtained starting from the analysis of acoustic emission produced by an engine, which have been acquired by a microphone placed under the vehicle hood. In the first part of the paper several upgrades to increase the overall performance of the speed extraction algorithm are presented and discussed, starting from the basic algorithm that has already demonstrated the methodology capability in a previous paper. In particular it has been considered a different signal sampling rate in order to extend the applicability of the methodology to a wider range of engines. Also a new processing procedure has been defined to increase the capability of the algorithm to tune on the frequency signal. A possible calibration procedure has been evaluated in order to set-up a threshold value in the algorithm procedure, based on a off-line analysis of the acoustic signal acquired with the engine running during a typical acceleration phase from idle up to the upper gear shift. In the results section, a new graphic representation of the algorithm performance has been introduced in order to obtain a sufficient clear idea of the performance of the rotational speed reconstruction algorithm. The trend of the percent error versus time and also an evaluation of the algorithm performance in every single second of the test are proposed. The results obtained demonstrate that the methodology is ready to be introduced in the ECU to enhance new strategies for the turbocharger control.

Across the world different regulations are applicable for side impact, each require a different restraint system approach. However it would be much more cost effective to develop one single restraint system suitable for all global requirements. An efficient methodology has been to optimize the restraint system for multiple load cases simultaneously, resulting in a restraint system specification that will ensure that global targets are met. The methodology combines the use of testing and efficient numerical simulation to find a solution in the most effective way. ABSTRACT Across the world different regulations are applicable for frontal impact, each require a different restraint system approach. However it would be much more cost effective to develop one single restraint system suitable for all global requirements. Flexible and reliable development approach has to be used for quick evaluations of various safety system configurations and conditions. An efficient methodology has been developed to optimize the frontal restraint system for multiple load cases simultaneously, Resultant restraint system specification to specification to meet global targets. The methodology combines the use of testing and MADYMO modelling techniques in combination with advanced DoE (Design of Experiments) analysis to find a solution in the most effective way. ABSTRACT In frontal crashes, one of the primary reasons for occupant injuries is hard contact with the vehicle interiors. While restraints like airbags, seat belt pre- tensioners etc. help in preventing direct contact of the upper body region; vehicle interiors play a critical role in controlling the lower body region injuries. Knee injuries can be controlled in various ways as follows:? Avoiding contact with the dashboard by use of buckle pre-tensioners etc • Using restraints like knee airbags • Optimizing the dashboard profile and stiffness at the contact locations All the above options have their own advantages and limitations. This paper explains the effect of dashboard stiffness tuning for controlling knee injuries in a frontal crash. The development methodology and some validation tools are discussed using a case study. ABSTRACT Bumper systems play an important role in energy management during vehicle accidents. Bumpers beams are generally designed to withstand impacts of up to 4 km/h (ECE42, FMVSS-581) and need to withstand low speed 15 km/h offset insurance crash tests to determine damageability and repairability features (RCAR-42) of vehicle design. Globalization of Automotive industry is forcing the designers to propose those designs, which can be introduced, to market quickly and which have lower costs and better quality. This paper presents work a novel design solution of a thermoplastic solitary bumper beam intended to reduce bumper weight and cost, meeting low speed damageability and RCAR impact requirements. A thermoplastic (PC/PBT) solitary beam is proposed that

The performance and design criteria for seat systems require that the seat be lighter for reduced fuel consumption while still meeting the safety requirements as required by legislation. The safety requirements for seats include headrests and seat back static and dynamic structural performance, seat belt anchorage and luggage retention capability, child seat anchorage and top tether requirements as defined by pertinent regulation. The interior space constraints require that the seat be thinner. The seat design is expected to address the growing concern for environmental friendliness. In addition to these main criteria, various additional features such as adjustable and stow-able design are required for customer delight. All these design objectives should be met within a given cost target. Conventional seating systems include a steel frame, with springs attached to provide support and flexibility to foam cushions. The steel frame is made up of several parts welded together. Weight of the seating system can be 80% of the weight of the interior of the vehicle. This paper deals with plastic front and rear seat designs that provide more than 20% weight reduction. The lighter seat improves the vehicle fuel efficiency, reducing CO2 emissions and the material of construction includes recyclable plastics and “green” polyurethane foam, making this design eco-friendly. Low cycle time of molding, reduced part count and assembly time, optimized contours for comfort and reduced material consumption lead to cost competitive design. The optimized structural properties and processability of various thermoplastics and thermoset polymer systems offer good stiffness and impact properties at fast cycle times. The combination of ease of processing, excellent mechanical behavior, dimensional stability and a wide operating temperature window make these materials a suitable choice for construction of seat systems. It is critical to combine the seat structure design with the appropriate choice of foam to provide comfort to the passenger, while minimizing weight and costs. Various implicit and explicit finite element analyses codes are used to simulate the process, structural and crash behavior in order to optimize the design, minimizing weight while meeting various regulatory requirements. This paper deals with the design, process, materials and the development methodology for plastic seats to meet various structural regulations and help fulfill the environmental demands on emissions and fuel consumption.

Internal combustion engine noise and vibration is a major issue for car makers, and this is even more important for High-Level Pick-ups and SUV’s which applies the modern diesel engines. One important player in this scenario is the second-order unbalanced forces vibration produced for the conventional inline 4 cylinder engine configurations, which leads to highfrequency excitation of vehicle’s structure and consequent internal noise. This paper studies the balancer shaft solution for the mentioned engine configuration, as well as major design alternatives and development process and issues. This paper also presents an example of balancer shaft design and development for a high speed diesel engine, as well as proposes a design-decision matrix methodology applied. Such methodology, which can be applied to any design or engineering case, is a way to design engineers to make the right decision amongst the different options that are always offered by a very simple and objective matrix.

Flex Track Drilling systems are being used increasingly in aerospace applications providing low cost, highly efficient automated drilling systems. Certain applications like circumferential splice drilling on large size airplane fuselages require multi spindle flex track systems working in tandem to meet production efficiency requirements. This paper discusses the development of a multi spindle flex track drilling system for a circumferential splice drilling on the 777 airplane. The multi spindle system developed uses a variety of flex track carriages attached to the flexible vacuum tracks to allow for offset or wide inside drilling. Segmented machine programmes allow these multiple machines to be deployed on the same circumferential splice on the airplane providing the multi spindle system. Interfacing of the multiple spindles is achieved by a custom OEM interface using a single screen thereby ensuring simplicity of operation. A central database location ensures that all programmes are current and maintains operational status of all holes being drilled. Tool life monitoring is also provided to ensure consistent tool changeovers for maintaining hole quality and process capability. Flexible track lengths can be spliced together for long lengths and shortened for clearance or areas using smaller programmes. This paper also discusses the development of the carriage hardware specific to the 777 airplane requirements using the methodology of adapting existing flex track system designs as well as point design specific to the 777 Fuselage Circumferential Splice Drilling Application. INTRODUCTION In the fall of 2007, a Boeing internal cross-functional team was chartered to investigate implementation of automation technologies to mitigate the challenges that have increased with higher production rates in 777 fuselage assembly. A technical report published by this team proposed the application of selective automation to the 777 Fuselage Integration processes. By implementing selective automation the benefits of reduced repetitive injuries, reduction of skin quality defects and lower cycle time in some of the fuselage integration processes would be realized. An additional benefit would also be the resultant consistent/repeatable and reliable process. These improvements would drive a better work environment, which would reflect on better attendance, less attrition and a higher employee morale. This Technology implementation would result in an improved product to the customer. After a detailed investigation of current build processes of longitudinal and circumferential splices it was determined that the focus should be on automation of the drilling of the circumferential splice on the 777-300 airplane, Aft fuselage section. To reduce developmental cost it was determined to use as much as possible offthe-shelf technologies with minimal developments needed to adapt to the 777 airplane requirements. Also taken into consideration was that the equipment chosen would need to be adaptable with few or no changes to current Floor Assembly Jig (FAJ) or floor mounted equipment (FME). SELECTIVE AUTOMATION PROPOSAL A technical evaluation of the longitudinal and circumferential splice drilling and fastening processes revealed that application of automation to selected portions of these processes would provide the greatest benefit for the investment incurred. On circumferential splice drilling and fastening processes it was discovered that the drilling processes constituted almost 70% of the total process time. These drilling processes included pilot drilling of holes, full size drilling of holes as well as countersinking processes. Any implementation of automation on these drilling processes would yield major gains in productivity including additional benefits of improved ergonomics, improved skin quality and overall an improvement of the production process and overall product quality. The study of the automation of the fastening processes for the circumferential splices yielded that gains realized by automation would not result in great improvements in productivity for these processes. Some of the gains would be offset by the additional process monitoring time as required by engineering specifications for the automated fastening processes. By focusing on the drilling processes only of the circumferential splices, the automation equipment requirements were also greatly simplified due to the omission of additional fastener insertion end effectors, clamp up equipment etc. This allowed the team to evaluate more options for the automated drilling equipment as many suppliers met the specifications for the drilling equipment but not for the drilling/fastening equipment, making it easier to obtain off the shelf automated drilling equipment. A time study along with an ergonomic study, combined with production process data including quality charts was compiled to help arrive at a decision for development and implementation of selective automation in 777 Fuselage Integration.

In modern four-stroke automotive engine, variable valve technology offer potential benefits for making a highperformance engine. In this paper, a novel electromechanical fully variable valve system (EMFVVS) is introduced. Just like the conventional mechanical variable valve systems, this design still uses a camshaft mechanism, but it is integrated into an electrohydraulic system to form an electromechanical system. The use of electrohydraulic system is to provide input hydraulic pulses to drive the engine valves cyclically. The output valve profile is controlled electronically by a common proportional pressure relief valve, and hence Late-ValveOpening + Early-Valve-Closing + Variable-Max-ValveLift can be achieved. The construction of the mathematical model of the variable valve system and its dynamic analysis, and some design issues are presented in this paper. Experimental and simulation results show that the novel electromechanical variable valve system can achieve fully variable valve timing and lift control without using complex control systems, and has the potential to eliminate the traditional throttle valve in the gasoline engines.

This paper describes how, according to the Fatality Analysis Reporting System (FARS, 1995-2004), over 20 percent of fatal frontal crashes are into fixed narrow objects such as trees and utility poles in real-world crashes. The Insurance Institute for Highway Safety (IIHS) has studied the frontal pole impact test since 2005, conducting a series of tests using passenger cars that are rated "Good" from the IIHS frontal offset test. Passenger cars were impacted into a 10-inch-diameter rigid pole at 64 kph. The alignment of the pole along the centerline of the vehicles in frontal impact was varied to study the influence on dummy injury metrics. This paper evaluates the frontal center pole test conducted by the IIHS. The IIHS tests 21 crashes impacted by the rigid pole using 5 vehicle models with two dummies in the front seat. Intrusions and dummy readings were reviewed according to the frontal offset rating criteria of the IIHS for structural performance and injury measurement. Post-crash investigations were conducted to examine the fracture or the deformation of the major front-end components. Finite element analysis was performed to characterize the frontal pole impact compared to the full frontal rigid barrier test and the IIHS 40% offset frontal impact test. The analysis investigated the distribution of the crash energy absorption by the front-end structure. Two vehicles that have different cross-section of the rails were simulated to compare the efficiency of crash energy absorption by different types of rails.

This paper provides a preliminary investigation of occupant kinematics for rear seat occupants involved in high-severity rear impacts. The effect of seatbelts equipped with or without a pyrotechnic pretensioner on restraining the rear seat adult occupant was evaluated in the paper. Further, the study examined the result of the occupant's seating alignment by comparing a Nominal Seating Position (NSP) to an occupant whose torso would be rotated forward to be placed in a Moderately Displaced Position (MDP) prior to impact. A series of eight sled tests were performed using a deceleration sled subjected to a delta-V of 30 mph. Instrumented HIII 50th and 5th ATDs were positioned in the outboard, rear seating positions. The study found that pretensioners had little effect on the occupant kinematics of rear seat occupants in either the NSP or the MDP. But, there were marked differences in kinematic evaluations between the occupant seating alignment configurations. HIC 15, HIC 36, Ncf, Nte, Ntf, peak chest acceleration, and peak, resultant pelvis acceleration all increased when the occupant's torso was displaced forward prior to the rear impact.

This paper describes how the coefficient of friction between a vehicle's tires and the roadway is a key parameter in any accident reconstruction. With the proliferation of vehicle dynamics software, it is often important to have more details regarding the tires interaction with the road than simply the average deceleration rate. Devices which can provide the peak friction as the braking develops, along with the average deceleration during the fully developed sliding phase, are necessary. There are now products widely available to the accident reconstruction market which provides these parameters as well as detailed acceleration versus time curves. The following products capable of providing these results were tested: Accelerex, Vericom VC3000, and two general-purpose accelerometers made by Silicon Designs and Dimension Engineering. Tests were conducted on wet and dry asphalt surfaces using a variety of passenger vehicles and transit buses which confirmed the agreement between these devices. Braking build-up time data is also presented in the paper.

This paper will discuss how markings or observable anomalies on vehicle seat belt restraint systems can be classified into two categories: Those caused by collision forces, or "loading marks" and (2) those created by non-collision situations, or "normal usage marks." A survey was conducted of both crash-tested and non-crash-tested vehicles in order to collect data on both categories of markings. This paper examines and analyzes the markings caused by both collision and non-collision load scenarios in order to illustrate and evaluate their unique differences as well as provide a general pattern of severity relative to different loading conditions.

This paper will describe an investigation that seeks to understand how rollovers occur in real-world crashes, both by studying real-world crashes and by analyzing vehicle-handling tests to gain insights into potential mechanisms of pre-crash loss of control. In particular, this study focuses on one type of rollover, namely single-vehicle rollovers that follow a pattern of the vehicle first leaving the roadway and then returning to the roadway typically out-of-control. The aims of this study included the following: (1) to describe the frequency and characteristics of single-vehicle rollovers involving an off-roadway excursion followed by a complete, if only temporary return to the roadway; (2) to the extent possible, given available data, to assess the nature and consequences of driver inputs during the crash sequence; (3) to define characteristics of crash scenarios which include a substantial proportion of this subset of single-vehicle rollovers. In order to accomplish these aims, case files from the National Automotive Sampling System, Crashworthiness Data System (NASS CDS, 1997-2001) were reviewed. The overall purpose of this review was to understand the mechanisms involved with loss of control and provide this information to support further research on preventing loss of control on the roadway subsequent to off-roadway excursion and roadway reentry. To further illustrate the mechanism that leads to loss of control when a vehicle returns to the roadway, the results of testing conducted to compare a vehicle's response to steering maneuvers on pavement versus the same steering maneuvers initiated on a road edge is presented. This paper presents the results of these tests, focusing on the effect that the change in surface has in amplifying the yaw rate and sideslip response of the vehicle. Finally, the results of the testing are compared to the insights gained from the NASS CDS real-world crash study, to garner further insight into some of the mechanisms involved with this type of accident.

This paper describes how, in the I-bumper (inflatable bumper) concept, two explosive airbags are released just before the main body-to-body crash in order to absorb the kinetic energy of colliding vehicles. The release also actuates other components in the I-bumper, including a movable bumper and an energy absorption morphing lattice structure. A small explosive charge will be used to deploy the airbag. A conventional airbag model will be used to reduce the crash energy in a controlled manner and reduce the peak impact force. An analytic model of the explosive airbag is developed in this paper for the I-bumper system and for its optimal design, while the complete system design (I-bumper) will be discussed in a separate paper. Analytical formulations for an explosive airbag will be developed and major design variables will be identified. These are used to determine the required amount of explosive and predict airbag behavior, as well to predict their impact on the I-bumper system. Related design guidelines and procedures will also be introduced. This new explosive airbag model will be implemented in Matlab, and will be validated with a high-fidelity model using an LS-DYNA simulation.

This paper explores the influence of the impact conditions on the dynamics and the severity of rollover crashes. It describes how causal connections are sought between the impact conditions and the crash attributes to which they lead. The paper begins by extending previously presented equations that describe the dynamics of an idealized vehicle-to-ground impact. It then considers the behavior of these equations under a variety of impact conditions that occur during real-world rollovers. Specifically, the equations of this impact model are used to explore the ways in which and the extent to which rollover dynamics and severity are influenced by the following factors: (1) the vehicle's shape and its orientation at impact; (2) its weight, center-of-mass location, and roll moment of inertia; (3) its translational speed; (4) its downward velocity; and (5) its roll velocity. Throughout this discussion, data from real-world and staged rollover crashes are used to give the parameter study an empirical basis.