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Delivering acceptable low end torque and good transient response is a significant challenge for all turbocharged engines. As downsized gasoline engines and Diesel engines make up a larger and larger proportion of the light-duty engines entering the market, the issue takes on greater significance. Several schemes have been proposed to improve torque response in highly boosted engines, including the use of electrical assist turbochargers and compressed air assist. In this paper we examine these methods with respect to their effectiveness in improving transient response and their relative performance along with some of the practical considerations for real world application. Results shown in this paper are from 1-D simulations using the Ricardo WAVE software package. The simulation model is based on a production light-duty Diesel engine modified to allow the introduction of compressed air at various points in the air-path as well as direct torque application to the turbocharger shaft (such as might be available from an electrical assist turbocharger). Whilst the 1-D simulation software provides a suitable environment for investigating the various boost assistance options, the overall air path performance also depends upon the control system. The introduction of boost assistance complicates the control in two significant ways: the system may run into constraints (such as compressor surge) that are not encountered in normal operation and the assistance introduces an additional control input. Production engine controllers are usually based on gain-scheduled PID control and extensive calibration. For this study, the non-linear nature of the engine together with the multiple configurations considered and the slower than real-time execution of 1-D models makes such an approach time consuming. Moreover, an ad-hoc approach would leave some doubt as to the fairness of comparisons between the different boost-assist options. Model Predictive Control has been shown to offer a convenient approach to controlling the 1-D simulations in a close to optimal manner for a typical Diesel VGT-EGR air path configuration. We show that the same technique can be applied to all the considered assistance methods with only modest calibration effort required. Copyright © 2012 SAE International.

Few previous publications investigate the possibility of combining multiple waste heat sources in a combustion engine waste heat recovery system. A waste heat recovery system for a HD truck diesel engine is evaluated for utilizing multiple heat sources found in a conventional HD diesel engine. In this type of engine more than 50% of heat energy goes futile. The majority of the heat energy is lost through engine exhaust and cooling devices such as EGRC (Exhaust gas recirculation cooler), CAC (Charge air cooler) and engine cooling. In this paper, the potential of usable heat recuperation from these devices using thermodynamic analysis was studied, and also an effort is made to recuperate most of the available heat energy that would otherwise be lost. A well-known way of recuperating this heat energy is by employing a Rankine cycle circuit with these devices as heat sources (single loop or dual loop), and thus this study is focused on using a Rankine cycle for the heat recovery system. Furthermore, this paper investigates the possibilities and challenges involved in coupling these different sources in a single Rankine cycle and the selection of suitable working fluid for this Rankine cycle. The study shows that with recuperation from these multiple sources it is possible to recover 5-10% of the otherwise wasted heat energy, which results in ~5% power increase. REFPROP was used for studying fluid properties, and the commercial software IPSEpro is used to build and simulate the Rankine cycle.

Prior papers have shown the potentials of gasoline-like internal combustion engines fitted with waste heat recovery systems (WHR) to deliver Diesel-like steady state fuel conversion efficiencies recovering the exhaust and the coolant waste heat with off-the-shelf components. In addition to the pros of the technology significantly increasing steady state efficiencies - up to 5 % in absolute values and much more in relative values - these papers also mentioned the cons of the technology, increased back pressures, increased weight, more complex packaging, more complex control, troublesome transient operation, and finally the cold start issues that prevent the uptake of the technology. This paper further explores the option to use Rankine cycle systems to improve the fuel economy of vehicles under normal driving conditions. A single Rankine cycle system is integrated here with the engine design. A latest turbocharged 1.6 liter direct injection engine has the coolant circuit modified to serve as pre-heater for the Rankine cycle fluid. This fluid is then vaporized and superheated in the boiler/super heater coaxial to the exhaust pipe located downstream of the turbocharger turbine and the closed coupled catalytic converter. The exhaust ports are insulated to reduce the heat losses.

This paper presents an investigation into Elastohydrodynamic (EHL) modeling of differential hypoid gears that can be used in coupling with Newtonian (or multibody) dynamics to study Noise, Vibration and Harshness (NVH) phenomena, such as axle whine. The latter is a noise of a tonal nature, emitted from differential axles, characterised by the gear meshing frequency and its multiples. It appears at a variety of operating conditions; during drive and coasting, high and low torque loading. Key design targets for differential hypoid gears are improved efficiency and reduced vibration, which depend critically on the formation of an EHL lubricant film. The stiffness and damping of the oil film and friction generated in the contact can have important effects and cannot be neglected when examining the NVH behaviour of hypoid gears. The operating conditions in hypoid gears are usually characterized by high load, relatively low speeds, angled flow and elliptical contact footprint of high aspect ratio. Some extrapolated/empirical equations to estimate friction and film thickness have been reported for moderate loads. However, their use in hypoid gears is questionable. Additionally, the majority of reported numerical models for film thickness and friction have not been applied under such operating conditions. In this paper a numerical model of EHL elliptical point contact has been presented to obtain the EHL film behaviour under the usual range of operating conditions of hypoid gears. Realistic engine torque-speed characteristics are used. For these conditions, the load share per teeth pair contact is in the region of 500-6000N. A suitable method of solution is applied to ease the convergence of the numerical method, namely the distributed line low relaxation effective influence Newton-Raphson method. As the result of the angled direction of the entraining flow in the contact of hypoid gear teeth pairs, this method has been found to be suitable, thus adopted. The geometric and kinematic input data for EHL calculations are calculated using Tooth Contact Analysis (TCA).

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.

International audience; This paper describes an innovative method to estimate the wall losses during the compression and combustion strokes of a gasoline engine using the cylinder pressure measurement. The estimation during the compression and combustion strokes allows to better represent the system during the combustion. A sliding mode observer is derived from a validated 0-D physical engine model and its convergence and stability are proved. The observer is validated using two different engine models: a one zone engine model and a two zones engine model with flame wall interaction. A good agreement between the estimation results and the model reference is observed, showing the interest of using closed loop strategies to estimate the wall losses in a SI engine.

Since the 1990's regulatory requirements for On-BoardDiagnostics (OBD) have continuously evolved with an increasing application of advanced electronics and control systems that have been adopted for automotive applications. The current and future demands on emissions and performance requirements are pushing the envelope with respect to management of complex control software strategies, hardware components and their interactions. This further challenges the implementation of OBD. In order to build a robust monitor for a complex system which has minimum risk of false detection, a thorough understanding of both system and components is required. In this paper, several methods will be presented that can be utilized to achieve a successful and robust diagnostic system implementation. Implementation begins with a discussion of the major challenges to achieve consistent performance in the base system control. A deep dive approach will provide new methodologies that can be applied to address the necessary diagnostics. This paper will address diagnostic fault handling based on symptoms, statistical methodologies for filtering out noise, and implementation of reference models for diagnostics. It will also discuss redefining the goal of OBD implementation on modern control systems that have multiple I/O as well as coupled and decoupled configurations.

The turn signal is a vital safety feature that is not only required to be built in as standard equipment on all vehicles, but their use by the driver in everyday driving is required by law. Since not all drivers are diligent at properly actuating turn signals in every situation, the use of the turn signal is less than 100%. However, despite the fact that turn signals are a crash prevention feature, no known study relating to turn signal usage rates is available from the National Highway Traffic Safety Administration, nor from the Department of Transportation, nor from any University, nor from other private safety organizations. This paper summarizes a first-ever published comprehensive study related to turn signal usage rates by everyday drivers and summarizes it in a simple, yet highly accurate naturalistic observation format with the following basic premise: A vehicle is observed to be turning in a situation that is deemed by the observer to require a turn signal: was the turn signal “on” or was it “off” in that observed vehicle? The summary of the cumulated data of turn signal usage is expressed in terms of a percentage usage rate. All turning drivers are unaware that their visible actions are data points in a study so the results are extremely accurate. Both turns as well as lane change usage rates are studied. Crash rates resulting from neglected turn signals are discussed, revealing that this neglect causes more crashes than distracted driving. The present turn signal system that relies solely on driver input can only be described as “defective”. The paper also discusses how patented Electronic Intelligent Turn Signals with Turn Signal Assist would vastly improve usage rates and therefore significantly lower crash rates for no added vehicle cost.

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.

ISO 26262 is the first comprehensive automotive safety standard that addresses the safety of the growing number of electric/electronic and software intensive features in today's road vehicles. This paper assesses the standard's ability to provide safety assurance. The strengths of the standard are: (1) emphasizing safety management and safety culture; (2) prescribing a system engineering development process; (3) setting up a framework for hazard elimination early in the design process; (4) disassociating system safety risk assessment from component probabilistic failure rate. The third and fourth strengths are noteworthy departure from the philosophy of IEC61508. This standard has taken muchneeded and very positive steps towards ensuring the functional safety of the modern road vehicles. SAE publications from industry show a lot of enthusiasm towards this standard. This paper suggested a number of items to be considered further strengthen the standard's ability to provide safety assurance. First, the Automotive Safety Integrity Level (ASIL) assessment may want to consider only the severity level, so that the subjectivity involved in likelihood assessment is eliminated. The ASIL assessment also needs to be standardized across manufacturers in order to address the tension between safety and business competitiveness. Government, industry consortium, and research institutions may want to work together on ASIL standardization efforts. Second, this standard provides little guidance on how to eliminate hazards in the design, but rather provides details on how to design and evaluate the effectiveness of component failure detection and control mechanisms. This paper identifies research that could be conducted on how to adapt the System Theoretic Accident Modeling and Process model during the design phase. Third, this standard gives detailed guidance on reliability engineering methods for component failures, but little on system safety design methods. Reliability and safety are different attributes of the system. This standard can be improved by further research on adapting system safety engineering methods to this standard. Fourth, the standard also substitutes good software systems engineering practices for software safety, although this is on par with other industry standards. Further research is needed to address software safety assurance. Fifth, the need for more detail in the safety assurance process and plan for product and operation phases of the product are discussed. Last, the needs for better design methods and safety assurance plan concerning driver/vehicle interaction design are also presented.

This paper deals with the ground testing of the technological demonstrator of the innovativeremotely controlled ETF airship. The testing activities are intended to validate the flight control system of the ETF, which is based on the thrust vectoring technology and represents one of the major innovations of the ETF design, together with the airship architecture. A research team of the Aeronautical and Space Department of the Polytechnic of Turin, in collaboration with Nautilus, a small Italian private company, has been working since a few years on the ETF (Elettra Twin Flyers). This airship is remotely-piloted, with high maneuverability capabilities and good operative features also in adverse atmospheric conditions. The Nautilus new concept airship features architecture and appropriate command system, which should enable the vehicle to maneuver in forward, backward and sideward flight and hovering with any heading, both in normal and severe wind conditions. To achieve these capabilities the ETF demonstrator3 has been conceived with a highly non conventional architecture based on a double hull with a central plane housing structure, propellers, on board electric system and payload . As primary command system, the aerodynamic control surfaces are replaced by six propellers, which are moved by electrical motors and allow the airship to be controlled and maneuvered in the whole flight envelope. In this paper the results of the preliminary testing runs are analyzed and the power requirement is compared with the performance of the Fuel Cell system, purposely developed for the ETF Demonstrator.

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.

Today CFD is an important tool for engineers in the automotive industry who model and simulate fluid flow. For the complex field of Under hood Thermal Management, CFD has become a very important tool to engineer the cooling airflow process in the engine bay of vehicles. To model the cooling airflow process accurately in CFD, it is of utmost importance to model all components in the cooling airflow path accurately. These components are the heat exchangers, fan and engine bay blockage effect. This paper presents CFD simulations together with correlating measurements of a cooling airflow system placed in a test rig. The system contains a heavy duty truck louvered fin radiator core, fan shroud, fan ring and fan. Behind the cooling module and fan a 1D engine silhouette is placed to mimic the blockage done by a truck engine behind the fan. Furthermore a simple hood is mounted over the module to mimic the air guiding done by the hood in an engine bay. The measurements monitor pressure and flow over the system. Supporting this examination is a set of 48 velocity probes in the radiator that measures the local velocity. The simulations of this system are correlated to measurements. Furthermore to support these simulations, specific simulations and measurements are conducted using the radiator only and the fan only. This is done to see how well each separate component is predicted in CFD and correlated back to measurements. This work is the continuation of work presented in [5] and identified in this paper is that one can simulate the cooling airflow system rather well with steady state CFD. However, fan modeling is sensitive and specific care has to be taken in order for these simulations to be accurate.

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.

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.

Characterization of combustion parameters of gaseous fuels is the main objective of a novel experimental laboratory, which recently became operational at Istituto Motori: the "Device for Hydrogen-Air Reaction Mode Analysis" (DHARMA in brief) project is meant to generate a systematic database on the burning properties of CH4, H2 and other species of interest, in conditions typical of i.c. engines. The experimental setup is based upon an optically accessible cylindrical bomb, where test are carried out on spherical expanding flames. High-speed shadowgraph is used to record the flame growth and to infer laminar burning parameters. Thorough details are given of the experimental apparatus and the data analysis. Experimental data are presented for the combustion in air of CH4 and of CH4/H2 mixtures: the percentage of hydrogen was 20% and 30% (vol.). The tests have been performed under the same conditions: equivalence ratio was 1.0, initial pressure and temperature were 6.0 bar and 293 K, respectively. Data analysis yielded the laminar burning velocity and Markstein length: the variation of these parameters has been evidenced as a function of the hydrogen content. The obtained results have been compared to those available in literature, showing a good agreement.

This paper proposes wall function models to simulate the heat transfer around a cylinder in cross flow with an isothermal and rough surface. The selected case has similitudes with aircraft wing icing: the ice roughness shape, height and distribution. Moreover, the flow is somewhat similar to that found on iced airfoil; and the surface is isothermal like when icing. The Reynolds-Averaged NavierStokes, turbulence, energy and mass conservation 7-equation system is solved by two Computational Fluid Dynamics (CFD) codes. To represent accurately the effects of roughness on the heat transfer, the present authors had to modify both codes and to propose new thermal wall functions for them. In addition, it was implemented a momentum wall function that is not so common in CFD codes but it is a standard in aircraft icing simulation. Basically, the present paper is focused on presenting the simulation results improvement obtained by the implementation of thermal wall functions that also considered the effect thermal resistance of viscous sub-layer on convective heat transfer. The numerical results were compared to experimental data of heat transfer around cylinders with an isothermally heated surface and equivalent sand grain roughness height of Ks=D = 900 10 5 . For the selected case, the flow regime was trans-critical at Reynolds numbers Re = ue D=n = 2:2 10 5 . Due to significant blockage effects present in the experimental data, the tunnel walls were also meshed and simulated. In sum, the implementation into CFD codes was considered adequate because the results were close to experimental data around the whole cylinder surface, not only along the leading edge or the separated region. The results accuracy were improved when compared with CFD factory original models. However, the results indicate that further works on wall functions and their validation are required before using CFD in wing aircraft icing.

During the past two decades the occurrence of ice accretionwithin commercial high bypass aircraft turbine engines undercertain operating conditions has been reported. Numerousengine anomalies have taken place at high altitudes that wereattributed to ice crystal ingestion such as degraded engineperformance, engine roll back, compressor surge and stall,and even flameout of the combustor. As ice crystals areingested into the engine and low pressure compressionsystem, the air temperature increases and a portion of the icemelts allowing the ice-water mixture to stick to the metalsurfaces of the engine core. The focus of this paper is onestimating the effects of ice accretion on the low pressurecompressor, and quantifying its effects on the engine systemthroughout a notional flight trajectory. In this paper it wasnecessary to initially assume a temperature range in whichengine icing would occur. This provided a mechanism tolocate potential component icing sites and allow thecomputational tools to add blockages due to ice accretion in aparametric fashion. Ultimately the location and level ofblockage due to icing would be provided by an ice accretioncode. To proceed, an engine system modeling code and amean line compressor flow analysis code were utilized tocalculate the flow conditions in the fan-core and low pressurecompressor and to identify potential locations within thecompressor where ice may accrete. Note that there is abaseline value of aerodynamic blockage due to low velocityair near the compressor inner and outer walls and bladesurfaces (boundary layer blockage). There is also a blockagedue to the blade metal thickness. In this study, the “additionalblockage” refers to blockage due to the accretion of ice on themetal surfaces. Once the potential locations of ice accretionare identified, the levels of additional blockage due toaccretion were parametrically varied to estimate the effectson the low pressure compressor blade row performanceoperating within the engine system environment. This studyincludes detailed analysis of compressor and engineperformance during cruise and descent operating conditionsat several altitudes within the notional flight trajectory. Thepurpose of this effort is to develop the codes to provide apredictive capability to forecast the onset of engine icingevents, such that they could help in the avoidance of theseevents.It has been reported that ice crystal accretion in gas turbineengines is dependent on the amount of mixed phaseconditions (liquid and solid) that exist. In addition, theproblem of ice accretion is highly multi-disciplinary, since itinvolves heat transfer from the air to the compressor metalsurfaces. The first phase of this study focuses on addressingthe thermodynamic cycle through the engine system code andthe mean line flow analysis through the compressor through aflight trajectory. The second phase of this study focuses on

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.

All surfaces of a cabin interior may contribute to the sound pressure at a certain reference position, e.g. the human's ear. Panel noise contribution analysis (PNCA) involves the measurement of the contribution of separate areas. This is an effective method to determine the effect of apparent noise sources at a specific location. This paper presents the latest developments on particle velocity based panel noise contribution analysis. In contrast to the traditional methods, the particle velocity approach is faster; it requires 3 days instead of weeks. While the theoretical base of the procedure in this paper is similar to previously published particle velocity based procedure, here the measurement protocol has now been simplified dramatically, which has reduced the measurement time even more to less than a day. The method and its implementation are explained in the paper and a full measurement procedure is reported. Four steps are required to determine and visualize the pressure contribution of the vehicle interior. In a first step, probes are positioned on predefined interior surfaces. Special probe mounting have been made to decrease the handling time. The second step is a measurement in a certain mode of operation. This step can be done in a laboratory but it is also possible to perform the measurement whilst driving the vehicle on the road. Stationary as well as non stationary running conditions like run ups are accessible and do not limit the applicability of the method. The third step is the determination of the transfer paths from the panels to a certain listening position. This measurement is done assuming reciprocity. A monopole source is placed on the listener position and the sound pressure is measured at the surface. In a fourth and last step the transfer paths are linked with the operational data gathered in step two. The results are then visualized using the predefined geometry model. This paper describes the measurement of a conventional car with a resolution of 137 panels. Since an array of 46 probes was used step 2 and step 3 are repeated 3 times.

Parabolic leaf spring plays a vital role in the suspension systems, since it has an effect on ride comfort and vehicle dynamics. Primarily, leaf spring endurance must be ensured. Presently, there are two approaches to design a leaf spring. In traditional method, fatigue tests should be repeated for each case considering different material, geometry and suspension hard points. However, it takes a long time and requires heavy budget to get the optimized solution. In the recent method, numerical approach is used to obtain the fatigue life and the leaf geometry against the environmental condition on the base of material properties. This paper presents a more precise method based on non-linear finite element solutions by evaluating the effects of the production parameters, the geometrical tolerances and the variations in the characteristics of the material. In other words, it is a hybrid method, between the traditional and the recent ones, which correlates the real life conditions and the results of computer aided engineering. The leaf springs in different characteristics have been produced and tested in the plant of OlgunCelik plant. The design methodology of this paper brings also a practical approach to the professionals in the industry. It aims to create a design tool with 2D FEA which is well correlated with 3D.The correlation of 3D and simple 2D methods with experiments are validated through a design of experiment (DOE) study. INTRODUCTION Parabolic leaf springs are the components of the suspension system. They perform isolation task in transferring vibration due to road conditions to body. There are various versions of the parabolic leaf springs such as parabolic, multi-parabolic and z-leaf spring. Development of a leaf spring is a long process which requires lots of test to validate the design and manufacturing variables. We have used CAE to shorten this development cycle by implying CAE as much as possible to reduce the tests. A systematic procedure is obtained where CAE and tests are used together. LEAF SPRING HYBRID DESIGN METHODOLOGY Every design method having CAE in the process must be based on validated virtual models. We have validated our finite element analysis models by experimental studies. These studies were carried out by the controlled manufacturing processes, measured manufacturing variables and comparison of the test results and virtual model using real variables. Primary output obtained from both test or finite element analysis of leaf springs are spring rate (force, displacement) and fatigue strength. In order to understand the parameters affecting fatigue strength of the leaf spring we have carried out a series of experiments in varying conditions. We have determined 26 parameters affecting fatigue results (Table1) depending on our experience and leaf spring boundary diagram (Table 2). Some of the parameters are major and other are minor. Design process starts with conceptual phase w general dimensions and shape of the leaf spring are determined. Conceptual phase decisions are based on experience and in-house software. Then a finite element model with nominal parameters is created. Design is optimized initially with nominal parameters. to reach required force-displacement curve, hence spring rate and stress level which is one of the important factors defining the fatigue strength. Then factors affecting fatigue are selected from the list given in Table 1 depending on project type, known tolerances, supplier data etc. The effect of these variables are studied in CAE by means of 3D and 2D models. This step is known as Design of Experiment (DOE). As a result of this DOE study, not only the CAD models but also decisions that are taken given in Table 1 are optimized. Prototypes are after having been produced. Figure 1. Hybrid Design Process

In this paper a state space representation of a turbocharged diesel engine is provided based on off-line least square method. Internal combustion engines show high nonlinear behavior due to complicated combustion phenomena and air flow dynamics inside the engine. In development phase of modern control methods like LQR controller, an accurate state space model with meaningful and measurable states is required. Identification is the method of deriving a mathematical model for dynamic systems based on inputoutput data. In this paper a mean value model of a turbocharged diesel engine is employed to generate demanded input-output data for identification purposes. This nonlinear mean value model predicts engine speed as a function mass of fuel injected per cycle, injection timing (ξ), ambient pressure and temperature and external loads. In the next step the simulation data is used to develop a state space model around idle mode operation state. Least square method is then employed to identify a linear time invariant state space model out of input-output data. In doing so, band limited white noise is used to generate demanded I/O data for model identification purposes. In the next step subsequent results are used to identify the LTI model based on LS. Load is considered as a disturbance while mass of injected fuel and injection timing is two main inputs of the model. Engine speed is considered the only output. Inlet and exhaust manifolds pressure, turbocharger speed and engine speed are 4 states of engine. Comparison between the nonlinear model results and state space model data show acceptable similarity. The results show that this scheme can be used for online identification of engine in fault detection and adaptive control processes.

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.

This paper describes how the increasing number of people over 65 years old is an important research topic in the area of impact biomechanics. The paper shows how finite element (FE) modeling can provide valuable support for related research. There were three objectives for this paper: (1) estimation of the representative age of the previously-documented Ford Human Body Model (FHBM) -- a FE model that approximates the geometry and mass of a mid-sized male; (2) development of FE models representing two additional ages; and (3) validation of the resulting three models to the extent possible with respect to available physical tests. Specifically, the geometry of the model was compared to published data relating rib angles to age, and the mechanical properties of different simulated tissues were compared to a number of published aging functions. The FHBM was determined to represent a range of 53 to 59 year old mid-sized males. The aforementioned aging functions were used to develop FE models representing two additional ages: 35 and 75 year old. The rib model was validated against human rib specimens and whole rib tests, under different loading conditions, with and without modeled fracture. In addition, the resulting three age-dependent models were validated by simulating cadaveric tests of blunt and sled impacts. The responses of the models, in general, were within the cadaveric response corridors. When compared to peak responses from individual cadavers similar in size and age to the age-dependent models, some responses were within one standard deviation of the test data. All the other responses, but one, were within two standard deviations.

This paper presents the business purpose, software architecture, technology integration, and applications of the Cummins Vehicle Mission Simulation (VMS) software. VMS is the value-based analysis tool used by the marketing, sales, and product engineering functions to simulate vehicle missions quickly and to gauge, communicate, and improve the value proposition of Cummins engines to customers. VMS leverages the best of software architecture practices and proven technologies available today. It consists of a close integration of MATLAB and Simulink with Java, XML, and JDBC technologies. This Windows compatible application software uses stand-alone mathematical models compiled using Real Time Workshop. A built-in MySQL database contains product data for engines, driveline components, vehicles, and topographic routes. This paper outlines the database governance model that facilitates effective management, control, and distribution of engine and vehicle data across the enterprise. This paper also presents four case studies on the applications of VMS to augment Cummins engineering and sales competencies by helping customers understand vehicle performance, optimize vehicle configurations, improve fuel economy, and reduce greenhouse gas emissions. INTRODUCTION The commercial vehicle industry has become increasingly aware of the interconnectedness of the components of a vehicle. Companies now research and engineer products around how each component interacts with other elements of the vehicle. Commercial software tools such as AVL Cruise, AVL ISAC, Advisor, GTDrive, and PSAT have evolved to support holistic vehicle integration, evaluate energy efficiency, and analyze componentlevel and system-level performance. To supplement the above commercial software tools, engine and vehicle manufacturers have also developed inhouse performance modeling software customized around their operating needs. Cummins uses an array of engine and vehicle validation tools as illustrated in Figure 1. Our suite of simulation tools, collectively called “CyberApps”, has been developed and validated over a span of 14 years. It operates a Unix based modeling platform and offers increasing degrees of fidelity by substituting mathematical models with hardware-in-loop Page 2 of 16 units of engine and vehicle subsystems. The simplest of these tools, “PureSim”, operates exclusively on MATLAB and Simulink models. It is this version of CyberApps that we have ported to Windows and adapted as the mathematical backbone of the analysis software that we describe in this paper. A discussion of the CyberApps mathematical models and validation process is outside the scope of this paper. Figure 1: Vehicle and engine testing and simulation tools used at Cummins Figure 2: Segmentation of users of engine-vehicle integration analysis software The in-house and commercial analysis tools we discussed above cater principally to the needs of advanced product engineering and research groups as illustrated in Figure 2. Consequently, these tools are complex, difficult to access, time-consuming and expensive for users outside of the engineering functions. These tools En gi ne C on tro l

Building prototype aircrafts is costly in tooling especially since only one aircraft is being built. Today's most common tooling strategy is to weld together a beam framework. Welded framework solutions have long lead times both in design and manufacturing and once the aircraft is assembled the tool becomes obsolete. Flexible tooling strategy uses non-welded tooling thus it can be changed and re-used for future products. Early version of a new aircraft model is always hampered by frequent changes in its design, which is cumbersome to handle in a welded framework solution. This paper presents a flexible assembly tooling solutions based on Flexapods and BoxJoint. The Flexapods are commercialized reconfigurable tooling units that are manually adjusted injunction with a laser tracker to a final positional accuracy of +/? 0,05 mm absolute accuracy. An operator software program called the Flexapod control panel collect metrology data in real-time and an operator screen show graphics on how to manually jog the Flexapod joints to reach the final Cartesian 3D-coordinate. The Flexapods are installed in a modular steel based framework solution called BoxJoint. A complete PLM package has been developed for the solution where the Flexapods are configured in CATIA using an add-on package to CATIA called the Flexapod configurator. All CATIA data is stored in ENOVIA. Once the Flexapod fixture is designed in CATIA a file, containing all Cartesian coordinates of the Flexapods, is exported and loaded into the Flexapod control panel on the workshop floor. A previous paper on the Flexapod as an early concept and a paper on BoxJoint have been presented at SAE Aerofast. This paper follows up on these results and presents a case study at SAAB Aeronautics for implementing the first industrial solution of Flexapods to build the military unmanned aerial vehicle - nEURON.

Copyright © 2009 SAE Japan and Copyright © 2009 SAE International – 2009 SETC. This paper is posted on this site with permission. As a user of this site, you are permitted to view this paper on-line, and print one copy of this paper at no cost for your use only. This paper may not be copied, distributed or forwarded to others for any use without permission from the copyright holder.

The air-cooled engine surfaces are generally provided with extended surfaces of high conducting materials called fins for enhanced heat transfer. One way to increase the rate of heat transfer is by increasing the fins surface area. However, increase in fin length introduces undesirable vibrations of the fins, which in turn radiate annoying high frequency noise. With the demand of quieter engines increasing, the vehicle manufacturers follow counter measures to minimize the fin vibrations. One trend in the two-wheeler industry is to put rubber dampers between the fins. These rubber dampers damps out the level of vibrations and the level of noise radiated is reduced. However, these rubber dampers have many disadvantages. Apart from the adding extra cost and a parallel manufacture process, these rubbers act as an insulating material, which impede the free flow of cooling air. The engine may get overheated and purpose of providing extended surface would not be satisfied. In this paper, effect of these rubber dampers on engine radiated noise and thermal performance is investigated. We discuss a systematic methodology on how to remove these rubbers by keeping the noise level same along with higher heat transfer from the engine surfaces. Results from experiments and numerical simulations for noise & vibration and computation fluid dynamics (CFD) with conjugate heat transfer are discussed. This paper describes a classic example of multi-disciplinary approach to solve real-world design problems.

The increasing use of distributed functions in vehicles can introduce unexpected and undesirable emergent behavior. This can be as a result of transient events such as sudden drops in the supply voltage. In this situation system behavior is often not adequately specified or controlled. This paper presents a novel approach to automotive electronic systems testing addressing robustness against low voltage transient conditions. The paper will discuss the technical output as well as performance in real-world test usage. The proposed approach uses a combination of pseudo-random number generator algorithms to generate parameterized supply voltage waveforms simulating low voltage transient conditions, used to drive the system-under-test (SUT). Two measures are used to judge whether the SUT has passed or failed the test; the detection of unintended recorded Diagnostic Trouble Codes (DTCs) from the error memory of each Electronic Control Unit (ECU) and the detection of unexpected system functionality by a human observer or automated vision system.

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.

This paper presents the design and development of a prototype Head-Up Display (HUD) interface that offer early notification warnings of potential collisions under unfavourable weather and traffic conditions. In this work we particularly focus our effort in the embedment of traffic congestion and sharp turn visual warnings in a working prototype interface. In turn we present the results of a large scale evaluation of the system on a group of forty users, which contrasted the use of the proposed HUD against a typical HDD. Finally the paper offers suggestions for further research and a tentative plan for future work.

A multimode transmission combines several power-split modes and possibly several fixed gear modes, thanks to complex arrangements of planetary gearsets, clutches and electric motors. Coupled to a battery, it can be used in a highly flexible hybrid configuration, which is especially practical for larger cars. The Chevrolet Tahoe Hybrid is the first light-duty vehicle featuring such a system. This paper introduces the use of a high-level vehicle controller based on instantaneous optimization to select the most appropriate mode for minimizing fuel consumption under a broad range of vehicle operating conditions. The control uses partial optimization: the engine ON/OFF and the battery power demand regulating the battery state-of-charge are decided by a rulebased logic; the transmission mode as well as the operating points are chosen by an instantaneous optimization module that aims at minimizing the fuel consumption at each time step. The controller is then implemented in a Simulink/Stateflow controller that can be used in Argonne's PSAT (Powertrain System Analysis Toolkit), a forward-looking powertrain simulation toolkit with dynamic plant models. As a result, the controller described in this paper is realistically implementable on an actual vehicle. Simulation results show the mode use and describe the practical operations of the system.

SAE paper 2010-01-0843: 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. Due to its potential for simultaneous improvement in fuel consumption and exhaust emissions, controlled autoignition (CAI) combustion has been subject to continuous research in the last several years. At the same time, there has been a lot of interest in the use of alternative fuels in order to reduce reliance on conventional fossil fuels. Therefore, this experimental study has been carried out to investigate the effect of alcohol fuels on the CAI combustion process and on the resulting engine performance. The experimental work was conducted on an optical single cylinder engine with an air-assisted injector. To achieve controlled autoignition, residual gas was trapped in the cylinder by using negative valve overlap and an intake air heater was used to ensure stable CAI combustion in the optical engine. Methanol, ethanol and blended fuels were tested and compared with the results of gasoline. The combustion processes were analysed through total chemiluminescence images captured with a high speed camera equipped with an intensifier. In addition, the effect of spark discharge was investigated. The images show that CAI combustion of alcohol fuels was characterized with fast and early autoignition combustion compared with pure gasoline. Chemiluminescence of the gasoline fuel was most visible and it decreased with increasing percentage of oxygenated fuels. During the re-compression stroke, chemiluminescence images of the gasoline engine indicated the presence of oxidation reactions. In the presence of spark discharge, the location of charge ignition was dominated by spark discharge at the center of cylinder while simultaneous autoignition sites were found around the periphery of the combustion chamber for non-spark-assisted ignition.

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.

The most common fan model to use in commercial CFD software today is the Multiple Reference Frame (MRF) model. This is at least valid for automotive under hood applications. Within the industry, for this typical application, this model is commonly known to under predict performance. This under prediction has been documented by the authors’ of this paper in SAE paper 2009-01-0178 and VTMS paper 2009-01-3067. Furthermore has this been documented by S.Moreau from Valeo in “Numerical and Experimental Investigation of Rotor-Stator Interaction in Automotive Engine Cooling Fan Systems”, ETC, 7th European Conference on Turbomachinery, 2007. In preceding papers a specific methodology of use has been documented and it has been shown that the MRF model under predicts performance for the airflow in a cooling system commonly with 14% in volumetric flow rate. This is for a system dominated by inertial effects. These 14% was shown to apply across fans of different sizes and designs hence illustrating a consistency of the fan model. In paper 2009-01-3067 a different methodology of use was documented which decreased the under prediction to 8%. In this paper the study has continued and is now presenting a more successful methodology of use which essentially removes the under prediction of the fan MRF model for most of fan operation, taking it for axial flow conditions within reasonable capabilities of reproducing tested geometry in a simulation environment, i.e. a difference of 0-1% between measurements and simulations.

Nowadays application of light alloys like aluminium in automobile industry has found a striking role. Higher strength over weight ratio which causes lower fuel consumption seems to be the first reason. Also some other reasons like ease of manufacturing, protection against corrosion and ease of recycling are other motivations for car designers to use various aluminium alloys as much as possible. Due to lack of variable thickness tubes, they have not found a lot of applications in the car component design. This paper aims to introduce these types of tubes to automotive industry. Also these tubes are one of the essential elements in the complementary processes like tube hydroforming and cause ease of production and decreasing risk of scrap in manufacturing cycles. Tube drawing is one of the mostly used methods for reducing thickness and/or diameter of tubes which, can be classified in four categories like sinking (without mandrel), float mandrel, fixed mandrel and ultrasonically moving mandrel. This paper presents numerical studies that have been done on the drawing tubes with variable thickness. The influence of process variables on material thinning and formability in 63.5mm outer diameter, 2.62 mm wall thickness AA6063 aluminium alloy tube, were investigated and optimised. Validation of the numerical simulation on the different parameters setting will be performed by comparing the final shape and deformation, measured from the tested part. Acceptable agreement between numerical and experimental results was observed.

This paper describes a strategy to simulate a dynamic model of a vertical takeoff and landing (VTOL) unmanned aerial vehicle (UAV) in flight transition from vertical climb to horizontal flight. Based on unique aerodynamic characteristics from CFD calculation and theoretical method the flight dynamics of ducted fan UAV is able to be modeled and simulated accurately. MATLAB/Simulink VRealm Builder is a design and modeling software tool for air vehicles that is capable of modeling the performance and flight dynamics during the conceptual and preliminary stage of aircraft design. To develop a control strategy, modeling and simulation of flight dynamics of ducted fan UAV is This paper describes a strategy to simulate a dynamic model of a vertical takeoff and landing (VTOL) unmanned aerial vehicle (UAV) in flight transition from vertical climb to horizontal flight. Based on unique aerodynamic characteristics from CFD calculation and theoretical method the flight dynamics of ducted fan UAV is able to be modeled and simulated accurately. MATLAB/Simulink VRealm Builder is a design and modeling software tool for air vehicles that is capable of modeling the performance and flight dynamics during the conceptual and preliminary stage of aircraft design. To develop a control strategy, modeling and simulation of flight dynamics of ducted fan UAV is necessary, because it not only can be applied to optimize dynamic model, but also be used to ensure the dynamic model match with control law.

This paper presented methods to determine the aerodynamic forces that act on an aircraft wing during flight. These methods are initially proposed for a simplified two degree-of-freedoms airfoil model and then are extensively applied for a multi-degree-of-freedom airfoil system. Different airspeed conditions are considered in establishing such methods. The accuracy of the presented methods is verified by comparing the estimated aerodynamic forces with the actual values. A good agreement is achieved through the comparisons and it is verified that the present methods can be used to correctly identify the aerodynamic forces acting on the aircraft wing models. INTRODUCTION During flight, aircraft wings always subject to varying aerodynamic loadings and as a consequence, generate varying structural responses. The varying aerodynamic loadings and structural responses are coupled to create a complicated vibration effect known as structural coupling dynamics. This effect can significantly reduce the aircraft’s service life. Even worse, sometimes the sustained vibration at natural frequencies of airfoils may lead to catastrophic structural failure. Recently, a number of researchers have dedicated tremendous effort to developing and choosing light material for the aircraft in order to obtain effective loading capacity. However, as the aircraft speed continues to increase, its structural flexibility is becoming a dominant concern in aircraft design and causing serious flutter in the airfoil and other components. Considering a typical cross-sectional plane of an airfoil, the gravity center G is usually located at 42% ~ 45% of the chord line, and the elasticity center is located at 38% ~ 40% of the chord line (Fig. 1). The gravity center is not coincident with the elastic center, which results in another coupling effect between the translational and rotational degree-of-freedoms of the aircraft wing. This coupling effect and the aforementioned structural coupling dynamics make it too difficult to correctly determine the aerodynamic forces acting on the aircraft wings. The current methods of studying the dynamic response of the aircraft structure consider the structural model and the aerodynamic model separately and therefore fails to precisely simulate the two coupling effects. In this paper, new methods are presented to determine the aerodynamic forces acting on aircraft wings during flight, which considers the model’s structural elasticity and aerodynamics as a combined mathematical system. The methods are initiated based on a simplified two degree-of-freedoms airfoil system and then they will be applied for a finite element aircraft wing model, which is a multi-degree-of-freedom system. The accuracy of the present methods will be verified by comparing the estimated aerodynamic forces with the actual values.

With the recent development of a multi spindle flex track drilling systems for aerospace applications, the challenges of testing and implementation on existing airplane programmes require unique technical methodologies and solutions. This paper discusses the technical approach, problems encountered and methodologies/solutions used to successfully implement a multi spindle flex track drilling system for circumferential splice drilling on the 777 airplane. The multi spindle system uses varieties of flex track carriages attached to flexible vacuum tracks for wide inside drilling. The hardware and software challenges encountered during the interfacing of the multi spindles are discussed as well as the complex problem of indexing and locating all detailed components of the splice accurately and with high repeatability. Design changes completed to make the equipment production ready along with the key hole feature probing hardware (Renishaw, Laser & Vision) and techniques are also presented in this paper. The usage of carbide drills with unique carbide material specification and drill geometry design is presented as part of the tool life optimization process. NC programming techniques and algorithms used to compensate for contour variability on circumferential splices are also discussed. Material handling equipment design and implementation process for this multi spindle flex track drilling cell is provided. The detailed test plan along with the incremental implementation methodology used to establish first a stable, then a robust and ultimately a completely optimized process with all technical variables accounted for is presented through the body of this paper.

Around 15% of traffic accident casualties in Europe are pedestrians. To date, most of the studies carried out only provide statistical information on the problem and few in-depth studies provide countermeasures which might correct it. There are many studies concerning pedestrian protection, which can be grouped into 'pedestrian modelling', 'biomechanical limits for pedestrians' and 'statistical analysis for pedestrian accidents'. Despite these studies, there is no predictive analysis of the benefits of pedestrian protection systems based on their intrinsic capabilities applied to a real accident sample. This paper describes a methodology for the evaluation of pedestrian protection systems based on the analysis of a wide sample of urban pedestrian accidents. All of them are analysed in-depth and reconstructed with PC-Crash. The effects of the frontal structure of the vehicles and several active systems, such as BAS and Pedestrian Detection Systems are evaluated. The paper includes the description of the methodology followed for a sample of approximately 140 pedestrian urban accidents in three cities of Spain (Madrid, Barcelona and Zaragoza) and the corresponding reconstructions generated with PC-Crash. Then, a methodology to simulate the passive and active improvements (including pedestrian friendly structure, BAS and Pedestrian Detection Systems) is defined and applied to all sample accidents. The results of these new simulations are used to evaluate the benefits of these systems. The main conclusions are discussed, accounting for the limitations of the study, which basically lie in the modelling of the Pedestrian Detection Systems. The methodology proposed in this paper can be applied to other vehicle safety devices to evaluate their effectiveness, based on the analysis of real accidents. All the results presented here come from a project partly funded by the Spanish Ministry of Industry. The full text of this paper may be found at: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0376.pdf For the covering abstract see ITRD E145407.

A common fan model to use in automotive underhood simulations is the Multiple Reference Frame (MRF) model and within the industry, for this specific application, this model is well known to under-predict performance. In a former paper, referenced 2009-01-0178, a simple 'speed correction' of the MRF model was proposed by the authors. The correction was shown to apply across different operating speeds for a specific fan. In this paper the generality and limitation of this correction across fans of different type, design and dimensions are investigated. Investigated in this paper is as well the sensitivity of the MRF model to specific methodology of use. In this paper it is shown that the speed correction of 14% proposed in the former paper applies widely, hence, although the MRF model is erroneous the error is consistent. A 680 mm fan of the similar design to the default (750 mm) choice was simulated and tested, in addition a different 750 mm fan with a more mixed flow design was simulated and tested, and the correction of 14% was shown to apply for these two fans as well. Furthermore is it also shown that the consistency of the MRF model applies with a consistent methodology of use; in its design, the MRF model needs a dedicated rotational volume around the rotating part, this needs to be chosen consistently by the end-user of the CFD software to achieve a consistent behavior of the MRF model. In this paper we show the sensitivity to the results done by the specific choice of rotational domain. In this paper a wiser choice of MRF region resulted in a significant drop in error and for this methodology a speed correction of only 8% was necessary.

The now-cancelled Constellation Program included the Orion, Altair, and Lunar Surface Systems project offices. The first two elements, Orion and Altair, were planned to be manned space vehicles while the third element was much more diverse and included several sub-elements. Among other things, these sub-elements were Rovers and a Lunar Habitat. The planned missions involving these systems and vehicles included several risks and design challenges. Due to the unique thermal operating environment, many of these risks and challenges were associated with the vehicles thermal control system. NASA s Exploration Technology Development Program (ETDP) consisted of various technology development projects. The project chartered with mitigating the aforementioned thermal risks and design challenges was the Thermal Control System Development for Exploration Project. These risks and design challenges were being addressed through a rigorous technology development process that was planned to culminate with an integrated thermal control system test. Although the technologies being developed were originally aimed towards mitigating specific Constellation risks, the technology development process is being continued within a new program. This continued effort is justified by the fact that many of the technologies are generically applicable to future spacecraft thermal control systems. The current paper summarizes the development efforts being performed by the technology development project. The development efforts involve heat acquisition and heat rejection hardware including radiators, heat exchangers, and evaporators. The project has also been developing advanced phase change material heat sinks and performing a material compatibility assessment for a promising thermal control system working fluid. The to-date progress and lessons-learned from these development efforts will be discussed throughout the paper.

Sublimators have been used for heat rejection in a variety of space applications including the Apollo Lunar Module and the Extravehicular Mobility Unit (EMU). Sublimators typically operate with steady-state feedwater utilization at or near 100%. However, sublimators are currently being considered to operate in a cyclical topping mode during low lunar orbit for Altair and possibly Orion, which represents a new mode of operation. This paper will investigate the feedwater utilization when a sublimator is used in this nontraditional manner. This paper includes testing efforts to date to investigate the Orbit-Averaged Feedwater Utilization (OAFU) for a sublimator.

This paper presents the findings of the trade study to evaluate carbon dioxide (CO2) sensing technologies for the Constellation (Cx) space suit life support system for surface exploration. The trade study found that nondispersive infrared absorption (NDIR) is the most appropriate high Technology Readiness Level (TRL) technology for the CO2 sensor for the Cx space suit. The maturity of the technology is high, as it is the basis for the CO2 sensor in the Extravehicular Mobility Unit (EMU). The study further determined that while there is a range of commercial sensors available, the Cx CO2 sensor should be a new design. Specifically, there are light sources (e.g., infrared light emitting diodes) and detectors (e.g., cooled detectors) that are not in typical commercial sensors due to cost. These advanced technology components offer significant advantages in performance (weight, volume, power, accuracy) to be implemented in the new sensor. The exact sensor design (light source, transmitting optics, path length, receiving optics and detector) will be specific for the Cx space suit and will be determined by the performance requirements of the Cx space suit. The paper further identifies specifications for some of the critical performance parameters as well as discussing the engineering aspects of implementing the sensor into the Portable Life Support System (PLSS). The paper then presents testing results from three CO2 sensors with respect to issues important to Extravehicular Activity (EVA) applications; stability, humidity dependence and low pressure compatibility. The three sensors include two NDIR sensors, one commercial and one custom-developed by NASA (for a different purpose), and one commercial electrochemical sensor. The results show that both NDIR sensors have excellent stability, no dependence on ambient humidity (when the ambient temperature is above the dew point) and operate in low pressure conditions and after being exposed to a full vacuum. The commercial electrochemical sensor was not suitable for the Cx space suit for surface exploration. Finally, the paper identifies a number of techniques currently under development that offer significant advantages for EVA applications. These include miniaturized, room temperature, solid electrolyte systems and advanced optical detectors.

This joint mobility KC lecture included information from two papers, "A Method for and Issues Associated with the Determination of Space Suit Joint Requirements" and "Results and Analysis from Space Suit Joint Torque Testing," as presented for the International Conference on Environmental Systems in 2009 and 2010, respectively. The first paper discusses historical joint torque testing methodologies and approaches that were tested in 2008 and 2009. The second paper discusses the testing that was completed in 2009 and 2010.

NVH labs at Tier 1 and Tier 2 suppliers have in the past 15 years implemented testing techniques to validate the NV performance of their products. Validation tests are most often conducted to check compliance of the product to vehicle OEM specifications, less often to truly assess NV performance. Vehicle OEM specifications are sometimes outdated, narrow in scope and require labtype of conditions, i.e. anechoic or hemi-anechoic environment, fixed microphone position and specific operating conditions. Tier 1 and 2 suppliers often find themselves in a situation in which they have to transport lab tests to the plant floor, as they are requested by their customer to ensure 100% shipped quality. In order to do so, they are faced with several technical and commercial challenges as vehicle OEM specifications often have no provisions for plant-floor boundary conditions and cycle time requirements. For cost reasons, the component manufacturer typically aims at adding NV performance checks to an existing test station, which poses additional challenges over using a completely redesigned test station. This paper will discuss the challenges encountered by Tier 1 and Tier 2 suppliers having to implement end-of-line NV testing for quality control. The paper will discuss these challenges for a few different automotive components, namely steering wheel clock springs, sunroofs, axles and shock absorbers. The authors will describe some of the challenges faced and the solution implemented at the end of the line as it relates to boundary conditions, absolute levels at feedback sensor and pass/fail criteria

This paper presents new developments on hot wire anemometer based panel noise contribution analysis. The used sensor allows the direct measurement of particle velocity. Some historical remarks are given and the latest developments of the technique are reported. Four steps are required to determine the panel noise contribution of the interior of a vehicle and to visualize the results in 3D. In a first step the probes are positioned on the interior surfaces and their x,y,z coordinates are measured. Based on these data a 3D geometry model is created. The geometry data are acquired using a specially designed 3D digitizer. The second step is a measurement in a certain mode of operation. This step can be done in a laboratory but it is also possible to perform the measurement whilst driving the vehicle on the road. Stationary as well as non stationary running conditions like e.g. run ups are accessible and do not limit the applicability of the method. The third step is the determination of the transfer paths from the panels to a certain listening position. This measurement is done reciprocally. In a fourth and last step the transfer paths are linked with the operational data gathered in step two. The results are then visualized using the 3D geometry model. This paper describes the measurement of a conventional car with a resolution of 180 panels. Since an array of 45 probes was used step 2 and step 3 had to be repeated 4 times. The complete measurement typically takes approximately 3 days.

An integrated numerical-experimental research activity has been carried out, in order to investigate the reliability of a modified, parallel version of KIVA3V, coupled with detailed kinetics, as an additional tool for the analysis of experimental results. In the proposed approach, fixed chemical species included in the reaction mechanism are used as markers for selection of the numerical methods to be used, aiming at exploiting, in every phase of the calculation, the most suitable solver. For validation purposes, pure n-Heptane was chosen as representative fuel model, both in experiments and computations. Calculated values are compared with experimental data collected on a single-cylinder diesel engine fuelled with pure n-heptane, in order to allow the direct use of a reaction mechanism for a single-component fuel. The single-cylinder research diesel engine employed in the work has the same architecture of a four-cylinder automotive engine currently on production, the FIAT 1.9 litre Multi-Jet engine. The selected reaction mechanism is the scheme developed by Liu et al. [ 1 ]. The measures are collected varying both the operative conditions and the engine compression ratio. The comparison between results from the simulations and measured data shows a very good agreement for conventional combustion conditions, confirming the model capability of capturing the CI combustion process behavior. Less accurate results are obtained in low temperature autoignition process simulations.

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.

Assessing the ability of a driver to see objects, pedestrians, or other vehicles at night is a necessary precursor to determining if that driver could have avoided a nighttime crash. The visibility of an object at night is largely due to the luminance contrast between the object and its background. This difference depends on many factors, one of which is the amount of illumination produced by a vehicle’s headlamps. This paper focuses on a method for digitally modeling a vehicle headlamp, such that the illumination produced by the headlamps can be evaluated. The paper introduces the underlying concepts and a methodology for simulating, in a computer environment, a high-beam headlamp using a computer generated light cluster. In addition, the results of using this methodology are evaluated by comparing light values measured for a real headlamp to a simulated headlamp.