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Thermoelectric generator (TEG) has received more and more attention in its application in the harvesting of waste thermal energy in automotive engines. Even though the commercial Bismuth Telluride thermoelectric material only have 5% efficiency and 250°C hot side temperature limit, it is possible to generate peak 1kW electrical energy from a heavy-duty engine. If being equipped with 500W TEG, a passenger car has potential to save more than 2% fuel consumption and hence CO2 emission reduction. TEG has advantages of compact and motionless parts over other thermal harvest technologies such as Organic Rankine Cycle (ORC) and Turbo-Compound (TC). Intense research works are being carried on improving the thermal efficiency of the thermoelectric materials and increasing the hot side temperature limit. Future thermoelectric modules are expected to have 10% to 20% efficiency and over 500°C hot side temperature limit. This paper presents the experimental synthesis procedure of both p-type and n-type skutterudite thermoelectric materials and the fabrication procedure of the thermoelectric modules using this material. These skutterudite materials were manufactured in the chemical lab in the University of Reading and then was fabricated into modules in the lab in Cardiff University. These thermoelectric materials can work up to as high as 500°C temperature and the corresponding modules can work at maximum 400°C hot side temperature. The performance loss from materials to modules has been investigated and discussed in this paper. By using a validated TEG model, the performance improvement using these modules has been estimated compared to commercial Bisemous Telluride modules.

The DEXA Cluster consisted of three closely interlinked projects. In 2003 the DEXA Cluster concluded by demonstrating the successful development of critical technologies for Diesel exhaust particulate after-treatment, without adverse effects on NO[x] emissions and maintaining the fuel economy advantages of the Diesel engine well beyond the EURO IV (2000) emission standards horizon. In the present paper the most important results of the DEXA Cluster projects in the demonstration of advanced particulate control technologies, the development of a simulation toolkit for the design of diesel exhaust after-treatment systems and the development of novel particulate characterization methodologies, are presented. The motivation for the DEXA Cluster research was to increase the market competitiveness of diesel engine powertrains for passenger cars worldwide, and to accelerate the adoption of particulate control technology.

The increasingly stringent limits on pollutant emissions from internal combustion engine-powered vehicles require the optimization of advanced combustion systems by means of virtual development and simulation tools. Among the gaseous emissions from spark-ignition engines, the unburned hydrocarbon (HC) emissions are the most challenging species to simulate because of the complexity of the multiple physical and chemical mechanisms that contribute to their emission. These mechanisms are mainly three-dimensional (3D) resulting from multi-phase physics - e.g., fuel injection, oil-film layer, etc. - and are difficult to predict even in complex 3D computational fluid-dynamic (CFD) simulations. Phenomenological models describing the relationships between the physical-chemical phenomena are of great interest for the modeling and simplification of such complex mechanisms. In addition, phenomenological models can be applied within simplified simulation environments, e.g., 0D-1D engine simulations, to enable predictions of HC emissions for a wide range of operating conditions. In this work, the development of phenomenological models to account for HC emissions from piston top-land crevices, wall flame quenching, and oil-film adsorption/desorption mechanisms is explained in detail. The model development is based on measurements and models from a single cylinder direct injection (DI) spark ignition (SI) research engine. Common modeling hypotheses and approaches from literature have been verified and further developed with 3D-CFD simulations. In particular, assumptions regarding local temperature and air-fuel ratio, which are necessary for HC modeling, have been developed on the basis of a zone post-processing of the 3D-CFD results. Additionally, a novel approach to describe HC post-oxidation, which is based on 0D-chemistry calculations, has been developed. The HC models have been implemented within a GT-POWER model of the engine in conjunction with a 0D two-zone combustion chamber description. The accuracy of the developed models has been tested against a large experimental database with varying engine load, speed, air to fuel ratio, valve timing, and oil/coolant temperature. The deviation in the HC emission prediction is mainly within 20% at warm engine operation. Higher deviations are observed at cold engine conditions because of the absence of secondary HC models which have not been considered in the present work.

Mass and efficiency are key performance indicators for the development and design of future electric power systems (EPS) for more-electric aircraft (MEA). However, to enable consideration of high-level EPS architecture design trades, there is a requirement for modelling and simulation based analysis to support this activity. The predominant focus to date has been towards the more detailed aspects of analysis, however there is also a significant requirement to be able to perform rapid high-level trades of candidate architectures and technologies. Such a capability facilitates a better appreciation of the conflicting desires to maximize availability and efficiency in candidate MEA architectures, whilst minimizing the overall system mass. It also provides a highly valuable and quantitative assessment of the systemic impact of new enabling technologies being considered for MEA applications. Without this capability, predesign assessments are often time consuming and of a qualitative manner. Accordingly, this paper will present a steady state pre-design analysis tool for MEA architectures, which enables analysis of the architecture performance at different stages of the flight profile. By providing drag and drop models of key MEA electrical power system components configured for common voltage and power levels, the tool facilitates the rapid construction of candidate architectures which then enables the subsequent quantitative assessment of overall system mass and efficiency. Key to the credibility and usefulness of this tool, is the appropriate marrying of validated fundamental mathematical models (for example in the evaluation of system losses), up-to-date data driven models (for example, relating to component masses or power densities) and the flexibility to incorporate new models of technologies under consideration. The paper will describe these core elements and present selected case studies demonstrating potential uses of the tool in architecture assessment and down-selection, technology impact, and design-point sensitivity analysis.

Environmental and economic issues related to the aeronautic transport, with particular reference to the high-speed one are opening new perspectives to pulsejets and derived pulse detonation engines. Their importance relates to high thrust to weight ratio and low cost of manufacturing with very low energy efficiency. This papers presents a preliminary evaluation in the direction of a new family of pulsejets which can be coupled with both an air compression system which is currently in pre-patenting study and a more efficient and enduring valve systems with respect to today ones. This new pulsejet has bee specifically studied to reach three objectives: a better thermodynamic efficiency, a substantial reduction of vibrations by a multi-chamber cooled architecture, a much longer operative life by more affordable valves. Another objective of this research connects directly to the possibility of feeding the pulsejet with hydrogen. This paper after a preliminary analysis of the pulsejet takes into account two necessary stages of this activity with the initial definition of the starting point of this activity, which aim to define an initial thermodynamic balance of a Lenoir cycle and a preliminary but effective estimation of the thermal problem. It analyses the heat transfer process through the wall of the combustion chamber of a pulsejet for aeronautic propulsion. The inside wall is exposed to burning gases with an average temperature of 1500 K, which oscillates with an amplitude 500 k and a frequency of 50 Hz. It has been considered the possibility of using Hydrogen injection to reduce the environmental impacts at the price of introducing a cooling water envelope at an average temperature of 80 °c. The water mass flow to ensure this condition has been evaluated and it has been evaluated both the average temperature profile within the wall and the effects of the oscillations of gas temperature inside the combustion chamber. Obtained results have allowed starting an effective activity through a radically new pulsejet architecture, which is expected to outclass any former pulsejet in term of operative life and of compression ratio with a consequent step increase in terms of thermodynamic efficiency.

The current paper is based on the French research program TESSA (“Transfert des Efforts des Sources Solidiennes Actives”). A specific task within TESSA project consists in the characterization of the measurements variability between several laboratories, of the blocked forces on a water pump of a heat engine. This paper focuses only on the measurements carried out at Vibratec laboratory. Two kinds of measurements have been carried out: direct measurements, using force sensors, which is the target of the inter-laboratory measurements, and an inverse method without force sensor requirements. Reproducibility and repeatability tests have been done in order to quantify the measurement variability within the same laboratory, in preparation for the inter-laboratory disparity analysis. Specific supports have been designed for each method: a rigid aluminum block for the direct method and a support dedicated to the inverse method, including a high modal density and modal damping in the frequency range of interest. The comparison of both methods shows that the inverse method is satisfying for the measurement of blocked forces on a “non-rigid” support and that it is possible to apply such methodology “in-situ”, with the source in its real environment. Mots clefs : Source solidienne, Effort de blocage, Methode inverse 22 Congres Francais de Mecanique Lyon, 24 au 28 Aout 2015

The aerodynamic drag, fuel consumption and hence CO2 emissions, of a road vehicle depend strongly on its flow structures and the pressure drag generated. The rear end flow which is an area of complex three-dimensional flow structures, contributes to the wake development and the overall aerodynamic performance of the vehicle. This paper seeks to provide improved insight into this flow region to better inform future drag reduction strategies. Using experimental and numerical techniques, two vehicle shapes have been studied; a 30% scale model of a Volvo S60 representing a 2003MY vehicle and a full scale 2010MY S60. First the surface topology of the rear end (rear window and trunk deck) of both configurations is analysed, using paint to visualise the skin friction pattern. By means of critical points, the pattern is characterized and changes are identified studying the location and type of the occurring singularities. The flow field away from the surface is then analysed using PIV measurements and CFD for the scale model and CFD simulations for the full scale vehicle. The flow field is investigated regarding its singular points in cross-planes and the correlation between the patterns for the two geometries is analysed. Furthermore, it is discussed how the occurring structures can be described in more generalized terms to be able to compare different vehicle geometries regarding their flow field properties. The results show the extent to which detailed flow structures on similar but distinct vehicles are comparable; as well as providing insight into the complex 3D wake flow.

This paper focuses on methods used to model vehicle surface contamination arising as a result of rear wake aerodynamics. Besides being unsightly, contamination, such as self-soiling from rear tyre spray, can degrade the performance of lighting, rear view cameras and obstruct visibility through windows. In order to accurately predict likely contamination patterns, it is necessary to consider the aerodynamics and multiphase spray processes together. This paper presents an experimental and numerical (CFD) investigation of the phenomenon. The experimental study investigates contamination with controlled conditions in a wind tunnel using a generic bluff body (the Windsor model.) Contamination is represented by a water spray located beneath the rear of the vehicle. The aim is to investigate the fundamentals of contamination in a case where both flow field and contamination patterns can be measured, and also to provide validation of modelling techniques in a case where flow and spray conditions are known. CFD results were obtained using both steady RANS and unsteady URANS solvers, combined with particle tracking methods. Steady RANS does not capture the wake structures accurately and this affects the contamination prediction. URANS is able to recover the large-scale wake unsteadiness seen in the experimental data, but the difference between the experimental and computational contamination distributions is still notable. The CFD is also able to provide further insight by showing the behaviour of particles of different sizes. Large particles are found to take on a ballistic trajectory and penetrate the wake. In contrast, small particles are shown to be less likely to become entrained into the wake.

The trend toward the adoption of a multiprocessor system on a chip (MPSoC) in critical real-time domains, like avionics or automotive, responds to the demand for increased computing performance to support advanced software functionalities. The other side of the coin is that MPSoCs challenge software timing analysis. This is so as co-running applications affect each other’s timing behavior on account of the interference incurred when accessing shared hardware resources, with the latter steadily increasing in number and complexity in every new generation of MPSoCs. For a solid and cost-contained software-timing validation approach, we contend that a taxonomy has to be developed to capture the different levels at which processors’ resources can be shared. Those levels are to be related to the conventional run-time software abstractions (e.g., task, thread, runnable) and the particular abstraction used to carry out contention analysis. From the standpoint of contention analysis, only the resources in those levels shared by the different run-time software entities need to be mastered and addressed by timing analysis, whereas the remaining resources can be safely disregarded. We tailor this approach to two of NVIDIA’s embedded platforms, TX2 and AGX Xavier, of particular relevance for the automotive domain. For the identified shared resources, we also characterize the contention that tasks can suffer and discuss the limitations and early approaches for modeling timing interference in shared hardware resources. This work has been partially supported by the SpanishMinistry of Science and Innovation under grants PID2019-107255GB and FJCI-2017 -34095; and the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 878752 (MASTECS) and the European Research Council (ERC) grant agreement No. 772773 (SuPerCom).

The aviation industry has witnessed a technological shift towards the More Electric Aircraft (MEA) concept. This shift has been driven by a number of perceived benefits including performance optimization and reduced life-cycle costs. Increased electrification within MEA has made aircraft electrical networks larger and more complex and this necessitates an increased electrical power offtake from the engine. The paralleling of multiple generation sources across the aircraft is one potential design approach which could help improve engine operability and fuel efficiency within more-electric aircraft platforms. Accordingly, this paper will investigate options for the realization of paralleled generation systems within the context of current design and certification rules. The paper first illustrates, through simulation, that MIL-STD-704F voltage envelopes may be breached for some interconnected electrical architectures under fault conditions. The paper then assesses various solution options to minimize the propagation of transients across the interconnected network and demonstrates their effectiveness with reference to appropriate power quality standards. The paper concludes by providing estimates of the impact of each of these solution options on the total weight of the electrical system, highlighting how different designs and operating strategies can influence the design at a systems level.

This paper summarizes the recent development of an adaptive aeroelastic wing shaping control technology called variable camber continuous trailing edge flap (VCCTEF). As wing flexibility increases, aeroelastic interactions with aerodynamic forces and moments become an increasingly important consideration in aircraft design and aerodynamic performance. Furthermore, aeroelastic interactions with flight dynamics can result in issues with vehicle stability and control. The initial VCCTEF concept was developed in 2010 by NASA under a NASA Innovation Fund study entitled "Elastically Shaped Future Air Vehicle Concept," which showed that highly flexible wing aerodynamic surfaces can be elastically shaped in-flight by active control of wing twist and bending deflection in order to optimize the spanwise lift distribution for drag reduction. A collaboration between NASA and Boeing Research & Technology was subsequently funded by NASA from 2012 to 2014 to further develop the VCCTEF concept. This paper summarizes some of the key research areas conducted by NASA during the collaboration with Boeing Research and Technology. These research areas include VCCTEF design concepts, aerodynamic analysis of VCCTEF camber shapes, aerodynamic optimization of lift distribution for drag minimization, wind tunnel test results for cruise and high-lift configurations, flutter analysis and suppression control of flexible wing aircraft, and multi-objective flight control for adaptive aeroelastic wing shaping control.

This paper presents the implementation of a vehicle and powertrain model of the parallel hybrid electric vehicle which can be used for several purposes: as a model for estimating fuel consumption, as a model for estimating performance, and as a control model for the hybrid powertrain optimisation. The model is specified as a multi-domain physical model in MATLAB Simscape, which captures the key electrical, mechanical and thermal energy flows in the vehicles. By applying hand crafted boundary conditions, this model can be simulated either in the forwards or backwards direction, and it can easily be simplified as required to address specific control problems. Modelling in the forwards direction, the driver inputs are specified, and the vehicle response is the model output. In the backwards direction, the vehicle velocity as a function of time is the specified input, and the engine torque, and fuel consumption are the model outputs. The model represents a parallel hybrid vehicle, which is being developed in the TC48 project. The project goal is to produce a prototype of a plug-in parallel hybrid system which is integrated into existing front wheel drive powertrains with modest additional engineering, cost, volume, and mass requirements. This paper explains the motivation for the project, and presents examples of the simulations which were used to guide the design. The vehicle simulation models used to evaluate the layout options are described and discussed. Sensitivity analyses are presented which informed the design decisions. A novel use of the Simscape component of MATLAB/Simulink which allows the same model structure to be used for both forwards and backwards simulations is demonstrated. This method has the possibility for more general application, and a toolbox is being developed which assists the generation of mathematical models of this type.

A vehicle driving on the road experiences unsteady flow conditions which are not generally reproduced in the development environment. This paper investigates the potential importance of this difference to aeroacoustics and hence to occupant perception and proposes a methodology to enable better ranking of designs by taking account of wind noise modulation.Two approaches of reproducing the effects of unsteady wind on aeroacoustics were investigated: an active wind tunnel Turbulence Generation System (TGS) and a quasi-steady approach based on measurements at a series of fixed yaw angles. A number of tools were used to investigate the onset flow and its impacts, including roof-mounted probe, acoustic heads and surface microphones. External noise measurements help to reveal the response of separate exterior noise sources to yaw.The noise experienced by the driver or passenger ear facing the side-glass is dominated by increased sound pressure levels when the adjacent side-glass is the leeward side of the vehicle with some non-linear effects as leeward yaw produces first accelerated flow and then separation.In part because of non-linearity in response to yaw, a challenging parameter for a wind tunnel simulation of dynamic yaw is achieving a wide enough variation in yaw angle and this work suggests that considering an appropriate range of yaw angles is more important than capturing the dynamics.In terms of passenger perception, the most important effect of a time-varying onset flow was demonstrated to be the modulation of wind noise rather than the increase in time-averaged cabin noise. For the case considered, at 130 km/h, the impact of wind-noise modulation was found to be equivalent to an extra 1-2 dBA in terms of passenger perception, while the increment in time-averaged cabin noise would be only 0.2 dBA.

[EN] Low pressure exhaust gases recirculation (LP-EGR) is becoming a state-of-the-art technique for Nitrogen oxides (NOx) reduction in compression ignited (CI) engines. However, despite the pollutant reduction benefits, LP-EGR suffers from strong non-linearities and delays which are difficult to handle, resulting in reduced engine performance under certain conditions. Measurement and observation of oxygen concentration at the intake have been a research topic over the past few years, and it may be critical for transition phases (from low pressure to high pressure EGR). Here, an adequate selection of models and sensors is essential to obtain a precise and fast measurement for control purposes. The present paper analyses different sensor configurations, with oxygen concentration measurements at the intake and exhaust manifold and combines observation techniques with sensor models to determine the potential of each configuration. Experimental results from a 2.2 l. diesel engine are used to validate the presented techniques.

The paper is based upon the work supported by Saudi Aramco Research and Development Center FUELCOM3 program under Master Research Agreement Number 6600024505/01. FUELCOM (Fuel Combustion for Advanced Engines) is a collaborative research undertaking between Saudi Aramco and KAUST intended to address the fundamental aspects of hydrocarbon fuel combustion in engines, and develop fuel/engine design tools suitable for advanced combustion modes. The authors would like to thank King Abdullah University of Science and Technology (KAUST) and the Clean Combustion Research Center (CCRC) for lab facilities and research support. Finally, the authors would like to convey gratitude towards the IC Engine Lab Safety Supervisor Adrian I. Ichim and the lab technician Riyad H. Jambi for their kind input and assistance in performing the experiments. The authors would like to express gratitude toward

The three-way-catalyst (TWC) is an essential part of the exhaust aftertreatment system in spark-ignited powertrains, converting nearly all toxic emissions to harmless gasses. The TWC’s conversion efficiency is significantly temperature-dependent, and cold-starts can be the dominating source of emissions for vehicles with frequent start/stops (e.g. hybrid vehicles). In this paper we develop a thermal TWC model and calibrate it with experimental data. Due to the few number of state variables the model is well suited for fast offline simulation as well as subsequent on-line control, for instance using non-linear state-feedback or explicit MPC. Using the model could allow an on-line controller to more optimally adjust the engine ignition timing, the power in an electric catalyst pre-heater, and/or the power split ratio in a hybrid vehicle when the catalyst is not completely hot. The model uses a physics-based approach and resolves both axial and radial temperature gradients, allowing for the thermal transients seen during heat-up to be represented far more accurately than conventional scalar (i.e. lumped-temperature) real-time models. Furthermore, we also use a physics-based chemical kinetics reaction model for computing the exothermic heat of reaction and emission conversion rate which is temperature and residence-time-dependent. We have performed an experimental campaign with a standard spark-ignited engine and a commercial TWC, where we measured steady-state operation and cold-start transient behavior. This experimental data allowed us to tune the model, where we found excellent matching between the measured and modeled tailpipe emissions. Modeling the radial temperature gradient improved the relative accuracy of the conversion efficiency by 15%, and simulations indicate the potential for an absolute improvement by 15 percentage points for some cases. Furthermore, the modeled TWC temperature evolution for a cold-start was typically within ±10 ° C of the measured temperature (with a maximal deviation of 20 °C). The proposed model thus bridges a gap between heuristic models suited for on-line control and accurate models for slower off-line simulation.

Contemporary trends are leading towards the electrification of aircraft for urban mobility applications. Accordingly, there is a high demand for advancements in light-weight, high voltage technologies to realize these new aircraft types. Driven by recent developments in the automotive industry, hybrid Pyrofuse protection devices have emerged as one such new candidate technology. Pyrofuses offer rapid clearance of fault currents, reduced cost and weight when compared to conventional mechanical breakers. In addition, Pyrofuses have the ability to tune the time-current curve to fit the application's fault response characteristics. However, Pyrofuses are non-resettable devices whose exclusive use for electrical protection could present potential operational hazards and certification challenges in aerospace applications. Model-based analysis will be critical in supporting this evaluation. Accordingly, this paper offers the first complete design methodology to transiently model Pyrofuse operation in MATLAB/Simulink, drawing characteristics from commercially available datasheets. This model is then utilized to undertake an initial protection coordination feasibility study for a candidate eVTOL electrical system architecture, exploring the associated device and system level operational capabilities and limitations. In particular, the results show that the Pyrofuse can offer a good degree of nuisance-tripping resilience against transient events whilst providing quick clearance of short circuit faults.

Bus drivers are a group at risk of often suffering from musculoskeletal problems, such as low-back pain, while bus passengers on the last-row seats experience accelerations of high values. In this paper, the contribution of K-seat in decreasing the above concern is investigated with a detailed simulation study. The K-seat model, a seat with a suspension that functions according to the KDamper concept, which combines a negative stiffness element with a passive one, is benchmarked against the conventional passive seat (PS) in terms of comfort when applied to different bus users’ seats. More specifically, it is tested in the driver’s and two different passengers’ seats, one from the rear overhang and one from the middle part. For the benchmark shake, both are optimized by applying excitations that correspond to real intercity bus floor responses when it drives over a real road profile. Then a human model is placed on the seats in order to compare their optimum solutions in terms of the user’s whole-body vibrations (WBVs), using objective comfort metrics. Based on the results, the K-seat improves significantly the comfort of the users (~92%) compared to the PS, while it achieves a similar decrease in the maximum values of the user’s back accelerations (~97%).

In the last years, the increasing concern for the environmental issues of IC engines has promoted the development of new strategies capable of reducing both pollutant emissions in atmosphere and noise radiation. Engines can produce different types of noise: 1) aerodynamic noise due to intake and exhaust systems and 2) surface radiated noise. Identification and analysis of noise sources are essential to evaluate the individual contribution (injection, combustion, piston slap, turbocharger, oil pump, valves) to the overall noise with the aim of selecting appropriate control strategies. Previous paper focused on the combustion related noise emission. The research activity aimed at diagnosing and controlling the combustion process via acoustic measurements. The optimal placement of the microphone was selected, where the signal was strongly correlated to the in-cylinder pressure development during the combustion process. Analysis and processing of the sound emission allowed the acoustic contribution of the combustion event to be isolated. Some indices capable of relating the combustion noise radiation back to the combustion development were defined. This paper presents an experimental activity devoted to analyze the entire noise generation process of a small displacement diesel engine. The purpose was to identify the contribution of the different sources (mechanical, combustion, fluid dynamic) to the overall emission. The methodology here proposed analyze the specific signature in the frequency domain of each source. The final objective was to use the microphone signal acquired in a proper selected location, to obtain indications about the effective strategies to achieve noise reduction. The repetitiveness of the measurements was guaranteed by a network encircling the engine. Microphones were placed in different positions and tests were performed in the complete engine operative field. In the paper, the experimental set-up is described, the methodology is presented. Results are then shown and discussed.

Vives College University and Kulab (KU Leuven University campus Ostend) in Belgium are undertaking an aeronautical research program about the development of a new Unmanned Aerial Vehicle (UAV). Since the UAV is completely electrically powered, the analysis of the energy management of the integrated electrical system was critical to the development of the UAV. LMS, A Siemens Business, i s involved in the project to support the development of a multi-physics simulation model for electro-thermal analysis of the aircraft. This paper reports on the subsequent investigation of integrating the detailed electrical system model for a Pilot-in-the-Loop simulation. In order to perform this simulation, the model of the electrical system was converted into a real-time simulation model. The aim was to perform more realistic flight simulations to evaluate the performance of the aircraft before its first flight by taking into account the electrical system's behavior. Furthermore, the behavior of the electrical system can be directly assessed during and after the Pilot-in-the-Loop tests. Additional research outcomes include the suitable level of detail of the electrical system that should be taken into account for Pilot-in-the-Loop simulations. The research outcome was evaluated with a number of simulations that assessed the effect of the electrical system model. It was concluded that the proposed simulation architecture is suitable to take into account the effect of the electrical system on the aircraft flight dynamics. ispartof: SAE Technical Papers vol:2014-September issue:September ispartof: SAE Aerospace Systems and Technology Conference location:Cincinnati, Ohio, USA date:23 Sep - 25 Sep 2014 status: published

Selective Catalytic Reduction (SCR) is a leading after treatment technology for the removal of nitrogen oxide (NOx) from exhaust gases (DeNOx). It presents an interesting control challenge, especially at high conversion, because both reagents (NOx and ammonia) are toxic, and therefore an excess of either is highly undesirable. Numerous system layouts and control methods have been developed for SCR systems, driven by the need to meet future emission standards. This paper summarizes the current state-of-the-art control methods for the SCR aftertreatment systems, and provides a structured and comprehensive overview of the research on SCR control. The existing control techniques fall into three main categories: traditional SCR control methods, model-based SCR control methods, and advanced SCR control methods. For each category, the basic control technique is defined. Further techniques in the same category are then explained and appreciated for their relative advantages and disadvantages. Thus this paper presents a snapshot of the current state of the art for the research area of SCR control. This is a very active field, and it is hoped that by providing a better understanding of the different control strategies already developed for SCR control, future areas of interest will be identified and developed with the ultimate aim of satisfying the increasingly stringent emissions legislation. Copyright © 2014 SAE International.

This paper presents a smart electric scooter system consisting of a microprocessor based vehicle controller (integrating an embedded regenerative braking controller), a 300W Permanent Magnet (PM) DC motor, two low-power DC-DC converters to form a higher power DC-DC converter pack, a motor controller, a supercapacitor bank and a capacitor cell balancing sub-system. During acceleration or forward motoring mode, the vehicle controller sets the DC motor into motoring mode to further utilizing motor controller regulate wheel speed and acceleration torque, whereas during deceleration or forward braking mode, sets the DC motor into braking mode and further utilizing regenerative braking controller regulate wheel speed and braking torque, as well as functions as a constant current (whose reference value is adjustable via a potentiometer) generator to charge the supercapacitor bank in a controllable fashion, hence not only successfully replacing frictional braking to certain degree, but also increasing the total energy efficiency dramatically owing to the low internal resistance and larger capacitance of the supercapacitor compared with other conventional regenerative braking systems via batteries. General structure of the smart system, control principle of the controllers, realization of measurement platform, experimental test setup as well as validation with results are all presented within this paper. Copyright © 2014 SAE International.

As is known, internal combustion engines based on Otto or Diesel cycles cannot complete the expansion process of the gas inside the cylinder, thus losing a relevant energy content, in the order of 30% of total. The residual energy of the unexpanded gas has been partially exploited through the use of an exhaust gas turbine for turbocharging the internal combustion engine; further attempts have been made with several compound solutions, with an electric generator connected to the turbocharger allowing to convert into electrical energy the quota power produced by the turbine which is not used by the compressor, or with a second turbine downstream the first to increase the exhaust gas energy recovery. Turbo-compound solutions were also employed in large marine Diesel engines, where the second turbine downstream the first was used to deliver more power to the main propeller shaft. In all these cases the overall efficiency increments remained within 5%. If completely recovered by the use of a properly designed expander-generator unit, the energy content of the unexpanded in-cylinder gas could substantially increase the overall efficiency of the thermal unit. In the present paper the authors evaluate, by means of simple yet effective calculations, the efficiency attainable by a thermal unit composed of a spark ignition engine endowed of an exhaust gas energy recovery expander connected to a proper generator. The proposed thermal unit, which is particularly suitable for hybrid propulsion solutions, has been evaluated both in the naturally aspirated and in the supercharged version. The efficiency of each thermal unit is also compared to reference baseline engine, thus highlighting the real benefit introduced by the adoption of the proposed thermal unit. As result, it was found that the complete and efficient recovery of the unexpanded gas energy has the potential to increase the overall efficiency of the propulsion system by 10-15%, depending on the characteristics of the thermal engine and of the exhaust energy expander-generator unit.

A computational fluid dynamics study of the scavenging process in a large two-stroke marine engine is presented in this work. Scavenging which is one of the key processes in the two-stroke marine engines, has a direct effect on fuel economy and emissions. This process is responsible for fresh air delivery, removing the combustion products from the cylinder, cooling the combustion chamber surfaces and providing a swirling flow for better air-fuel mixing. Therefore, having a better understanding of this process and the associated flow pattern is crucial. This is not achievable solely by experimental tests for large engines during engine operation due to the difficulties of measuring the flow field inside the cylinder. In this study, the axial and tangential velocities are compared and validated with the experimental results obtained from Particle Image Velocimetry (PIV) tests [1]. The simulations are conducted using both Unsteady Reynolds Averaged Navier Stokes (URANS) and Large Eddy Simulation (LES) turbulence models. We observe in general, there is a good agreement between the numerical and experimental results. The flow inside the cylinder is studied in different locations related to the bottom of the scavenging ports during the period with open exhaust valve. Moreover, the replacement of combustion products with fresh scavenge air is analysed. The effective flow angle is calculated for the air flow through the scavenging ports. It is found that the effective flow angle is different from the geometrical angle of the ports (20o). Results illustrate better performance of LES, especially in the prediction of the tangential velocity which is crucial for the simulation of an accurate swirl and air-fuel mixing inside the marine engines. LES predicts a uniform profile for the tangential velocity at the top of cylinder which is consistent with the experimental results while URANS predicts a solid body rotation.

This paper is based upon work supported by Saudi Aramco Research and Development Center FUELCOM3 program under Master Research Agreement Number 6600024505/01.FUELCOM (Fuel Combustion for Advanced Engines), is a collaborative research undertaking between Saudi Aramco and KAUST intended to address the fundamental aspects of hydrocarbon fuel combustion in engines, and develop fuel/engine design tools suitable for advance combustion modes.

Many modern vehicles have blunt rear end geometries for design aesthetics and practicality; however, such vehicles are potentially high drag. The application of tapering; typically applied to an entire edge of the base of the geometry is widely reported as a means of reducing drag, but in many cases, this is not practical on real vehicles. In this study side tapers are applied to only part of the side edge of a simplified automotive geometry, to show the effects of practical implementations of tapers.The paper reports on a parametric study undertaken in Loughborough University’s Large Wind Tunnel with the ¼ scale Windsor model equipped with wheels. The aerodynamic effect of implementing partial side edge tapers is assessed from a full height taper to a 25% taper in both an upper and lower body configuration. These were investigated using force and moment coefficients, pressure measurements and planar particle image velocimetry (PIV). These geometries showed that the drag reductions are maximised with a 50% span, generating a vertically symmetric wake and less taper drag contribution when compared to a full span taper.

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.

The bus sector is currently lagging behind when it comes to implementing autonomous systems for improved vehicle safety. However, in cities such as London, public transport strategies are changing, with requirements being made for advanced driver-assistance systems (ADAS) on buses. This study discusses the adoption of ADAS systems within the bus sector. A review of the on-road ADAS bus trials shows that passive forward collision warning (FCW) and intelligent speed assistance (ISA) systems have been successful in reducing the number of imminent pedestrian/vehicle collision events and improving speed limit compliance, respectively. Bus accident statistics for Great Britain have shown that pedestrians account for 82% of all fatalities, with three quarters occurring with frontal bus impacts. These statistics suggest that the bus forward collision warning system is a priority for inclusion in future vehicles to enhance the driver’s direct vision, and to increase reaction time for earlier brake application. Almost 80% of bus occupant casualties occurred in non-impact situations, mainly during acceleration/deceleration events. Therefore, care must be taken in implementing autonomous braking in buses, to ensure that it does not cause an increased number of deceleration events beyond the safe stability limits for passengers. Real on-road drive cycle data has shown that while instances of unsafe braking events do not occur regularly, there are instances of braking events that would present a hazard to both seated and standing passengers, therefore systems that would mitigate these issues would have real benefits to both passenger comfort and safety. During tests to simulate the use of the vehicle retarder for an autonomous braking system, deceleration rates largely remained safely within standee and seated passenger stability limits, whereas an emergency stop test showed a peak deceleration 3.5 times the limit of a standee supported by a vertical handrail, and 4 times the limit for a forward/backward facing seated passenger.

International audience; This paper touches on the mass transport phenomenon in the exhaust gas recirculation (EGR) of a gasoline engine air path. It presents the control-oriented model and control design of the burned gas ratio (BGR) transport phenomenon, witnessed in the intake path of an internal combustion engine (ICE), due to the redirection of burned gases to the intake path by the low-pressure EGR (LP-EGR). Based on a nonlinear AMESim® model of the engine, the BGR in the intake manifold is modeled as a state-space (SS) output time-delay model, or alternatively as an ODE-PDE coupled system, that take into account the time delay between the moment at which the combusted gases leave the exhaust manifold and that at which they are readmitted in the intake manifold. In addition to their mass transport delay, the BGRs in the intake path are also subject to state and input inequality constraints. The objective of the control problem is to track a reference output profile of the BGR in the intake manifold, taking into account the transport delay and the state (output) and input constraints of the system. In this aim, two indirect optimal control approaches are implemented and compared, the discretize-then-optimize approach and the optimize-then-discretize approach. To account for the state inequality constraints, both methods are equipped with techniques for constrained optimization such as the augmented Lagrangian and the UZAWA methods. The necessary conditions of optimality are formulated, in each of both cases, and the resulting equations are solved numerically using the projected gradient-descent method, which ensures the non-violation of the input inequality constraints. The novelty of the work lies in considering the system's constraints and the infinite-dimensionality of the mass transport phenomenon governing it. The merits of the time-delay model and the model-based control design are illustrated on the nonlinear® AMESim model on which the mathematical model is based.

The paper is based upon work supported by Saudi Aramco Research and Development Center FUELCOM3 program under Master Research Agreement Number 6600024505/01. FUELCOM (Fuel Combustion for Advanced Engines) is a collaborative research undertaking between Saudi Aramco and KAUST intended to address the fundamental aspects of hydrocarbon fuel combustion in engines, and develop fuel/engine design tools suitable for advanced combustion modes. The author would like to thank King Abdullah University of Science and Technology (KAUST) and the Clean Combustion Research Center (CCRC) for lab facilities and research support. Last but not least, the authors would like to convey gratitude towards the IC Engine Lab Safety Supervisor Adrian I. Ichim and the lab technician Riyad H. Jambi for their kind input and assistance in performing the experiments.

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.

© 2020 Loughborough University. Understanding and predicting in-cylinder flow structures that occur within compression-ignition engines is vital if further optimisation of combustion systems is to be achieved. To enable this prediction, fully validated computational models of the complex turbulent flow-fields generated during the intake and compression process are needed. However, generating, analysing and interpreting experimental data to achieve this validation remains a complex challenge due to the variability that occurs from cycle to cycle. The flow-velocity data gathered in this study, obtained from a single-cylinder CI engine with optical access using high-speed PIV, demonstrates that significantly different structures are generated over different cycles, resulting in the mean flow failing to adequately reflect the typical flow produced in-cylinder. Additionally, this high level of variability is shown by the work to impact the assessment of turbulence throughout the cycle, influencing the values often used to validate mathematical models. The original work in this paper analyses experimental PIV data from the single cylinder engine, to characterise the differences between individual cycles' bulk flow structures and the resultant turbulent fields. The analysis approach presented uses proper orthogonal decomposition (POD) and spatial filtering to interpret the progression of the flow structures and energy throughout compression, giving an understanding of the actual flow structures that are most likely to be produced in the engine. This analysis of the data provides a meaningful understanding of the nature of the bulk flow variations and how the turbulent field develops over a given cycle, from the intake stroke to the end of compression.

Since, ice accretion can significantly degrade the performance and the stability of an airborne vehicle, it is imperative to be able to model it accurately. While ice accretion studies have been performed on airplane wings and helicopter blades in abundance, there are few that attempt to model the process on more complex geometries such as fuselages. This paper proposes a methodology that extends an existing in-house Extended Messinger solver to complex geometries by introducing the capability to work with unstructured grids and carry out spatial surface streamwise marching. For the work presented here commercial solvers such as STAR-CCM+ and ANSYS Fluent are used for the flow field and droplet dispersed phase computations. The ice accretion is carried out using an in-house icing solver called GT-ICE. The predictions by GT-ICE are compared to available experimental data, or to predictions by other solvers such as LEWICE and STAR-CCM+. Three different cases with varying levels of complexity are presented. The first case considered is a commercial transport airfoil, followed by a three-dimensional MS(1)-317 swept wing. Finally, ice accretion calculations performed on a Robin fuselage have been discussed. Good agreement with experimental data, where applicable, is observed. Differences between the ice accretion predictions by different solvers have been discussed.

Diesel engine has fuel combustion capability in various high density oil such as residual fuels or biofuels derived from fossil or living matter. But for commercial use, these fuels except bio diesel fuel (BDF) should be heated, separated and filtered by equipment and dosed or mixed with additive or distillate oil etc. before being supplied to the engine in order to improve combustibility. This study aims to illuminate fuel characteristic of blend contained woody pyrolysis oil (WPO) which is high viscosity and incombustible, and dimethyl ether (DME) whose emission of combustion has no soot particle. This paper describes thermo-physical property of neat WPO and the blend on the basis of the evaluation of fuel fluidity by measurement and calculation of viscosity. According to the result, it was confirmed that the fluidity of WPO was improved by mixing DME and the approximate viscosity expressions at any temperature of WPO and the blend were good accuracy.

In this paper the effects of a rough underbody on the rear wake structure of a simplified squareback model (the Windsor model) is investigated using balance measurements, base pressure measurements and two and three component planar PIV. The work forms part of a larger study to develop understanding of the mechanisms that influence overall base pressure and hence the resulting aerodynamic drag. In the work reported in this paper the impact of a rough underbody on the base pressure and wake flow structures is quantified at three different ground clearances. The underbody roughness has been created through the addition of five roughness strips to the underbody of the model and the effects on the wake at ground clearances of 10.3%, 17.3% and 24.2% of the model height are assessed. All work has been carried out in the Loughborough University Large Wind Tunnel with a scale model giving a blockage ratio of 4.4% for a smooth under-body or 4.5% with the maximum thickness roughness strips. The tests are conducted with a fixed ground plane. Results are presented for the base pressure distribution and these are compared against the stream-wise PIV results. This work demonstrates the need for rough underbody structures to be considered during base pressure investigations before any model scale work is conducted due to their influence on the wake structures. Copyright © 2013 SAE International.

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).

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.

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.

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.

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.

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.

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.

Due to titanium’s excellent strength-to-weight ratio and high corrosion resistance, titanium and its alloys have great potential to reduce energy usage in vehicles through a reduction in vehicle mass. The mass of a road vehicle is directly related to its energy consumption through inertial requirements and tire rolling resistance losses. However, when considering the manufacture of titanium automotive components, the machinability is poor, thus increasing processing cost through a trade-off between extended cycle time (labor cost) or increased tool wear (tooling cost). This fact has classified titanium as a “difficult-to-machine” material and consequently, titanium has been traditionally used for application areas having a comparatively higher end product cost such as in aerospace applications, the automotive racing segment, etc., as opposed to the consumer automotive segment. Herein, the problems associated with machining titanium are discussed, and a review of cutting tool technologies is presented that contributes to improving the machinability of titanium alloys. Additionally, nonconventional machining techniques such as High Speed Machining and Ultrasonic Machining are also reviewed. Also discussed are additional factors that need to be considered especially pertaining to the machining of titanium alloys, a crucial one being the non-conformity with standard tool wear models. Subsequently, the results of a controlled milling experiment on Ti-6Al-4V is presented, to evaluate the relationship between certain tool preparation/process parameters and tool wear for a comparison with traditional wear models. INTRODUCTION Titanium is the seventh most abundant metal and the fourth most abundant structural metal in earth’s crust behind aluminum, iron and magnesium. Titanium and its alloys are considered as alternatives in many engineering applications due to their superior properties such as retained strength at elevated temperatures, high chemical inertness and resistance to oxidation. Titanium has traditionally been utilized as a lightweight, very strong and exceedingly corrosion resistant material in the aerospace industry, electric power plants, seawater desalination plants, and heat exchanges. Also, it has been used in industrial applications such as petroleum refining, nuclear waste storage, food processing, pulp and paper plants, and marine applications [1]. Nevertheless, when considering the use of titanium as an automotive component material, there are several conflicting aspects that must be addressed. First of all, the cost of titanium is relatively high in comparison to other common engineering materials such as aluminum, magnesium, and steel. For this reason, it specifically calls for implementation and use only when extreme conditions are to be met, such as in the aerospace industry. The main reason for the increased cost is due to the limited demand from other market segments, thus making the extraction of the titanium ore expensive. Also, the processing costs for converting the ore into commercially usable titanium and its alloys is extensive and requires special processing procedures and involves vast batch production and careful process control, making them difficult to automate. Second, the difficulty in efficiently manufacturing titanium components has a significant adverse effect on processing cost which is mainly due to its low modulus of elasticity and high yield stress. Another manufacturing concern that arises during the machining of titanium is its susceptibility to work hardening during the cutting process and its tendency to react with many cutting tool materials causing substantial tool wear. Additionally, titanium has poor thermal conductivity properties, making heat dissipation a problem, again contributing to higher tool wear. Of primary concern however is the lack of material grade development outside the aerospace industry in which most of the alloys are developed for extreme conditions. This severely limits the currently available grades suited for automotive applications. Thus, a suite of lower strength alloys with properties specially catered for commercial automotive use needs to be developed. This paper examines most of the issues traditionally associated with the machinability of titanium and titanium alloys. As mentioned before, some methodologies and techniques are recommended for mitigating the non-desirable effects during titanium processing and analyzed in more detail, is its unique tool wear characteristics especially in light of manufacturing automotive components. Thus, this study is expected to primarily assist in the reduction of the processing cost of titanium and its alloys for automotive component manufacture. This will help reduce the operating cost of a road vehicle in terms of better fuel economy due to the reduced mass, which in turn translates to better energy efficiency. TITANIUM IN THE AUTOMOTIVE

A protocol has been developed that produced the type of lunar soil abrasion damage observed on Apollo spacesuits. This protocol was then applied to four materials (Kevlar (DuPont), Vectran (Kuraray Co., Ltd.), Orthofabric, and Tyvek (DuPont)) that are candidates for advanced spacesuits. Three of the four new candidate fabrics (all but Vectran) were effective at keeping the dust from penetrating to layers beneath. In the cases of Kevlar and Orthofabric this was accomplished by the addition of a silicone layer. In the case of Tyvek, the paper structure was dense enough to block dust transport. The least abrasive damage was suffered by the Tyvek. This was thought to be due in large part to its non-woven paper structure. The woven structures were all abraded where the top of the weave was struck by the abrasive. Of these, the Orthofabric suffered the least wear, with both Vectran and Kevlar suffering considerably more extensive filament breakage.

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.

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.

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.