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International audience; Recent work in the area of safety analysis has shown that system Fault Trees and Failure Modes and Effects Analyses (FMEAs) can be automatically derived from a topological model of the system that has been annotated with local, component-level, specifications of failure. In this paper, the concept of a component failure specification is extended to enable description and reuse of generalized patterns of failure behaviour that are commonly exhibited by components. A language for the description of such patterns is specified, useful patterns are presented and the use of such patterns is demonstrated on an example of a Time-Triggered system. The paper tentatively concludes that careful reuse of failure patterns in conjunction with automated fault tree and FMEA synthesis algorithms can help to rationalize, and simplify, complex safety assessments.

The major contribution of this paper is to propose a low-cost accurate distance estimation approach. It can potentially be used in driver modelling, accident avoidance and autonomous driving. Based on MATLAB and Python, sensory data from a Continental radar and a monocular dashcam were fused using a Kalman filter. Both sensors were mounted on a Volkswagen Sharan, performing repeated driving on a same route. The established system consists of three components, radar data processing, camera data processing and data fusion using Kalman filter. For radar data processing, raw radar measurements were directly collected from a data logger and analyzed using a Python program. Valid data were extracted and time stamped for further use. Meanwhile, a Nextbase monocular dashcam was used to record corresponding traffic scenarios. In order to measure headway distance from these videos, object depicting the leading vehicle was first located in each frame. Afterwards, the corresponding vanishing point was also detected and used to automatically compute the camera posture, which is to minimize the interference caused by camera vibration. The headway distance can hence be obtained by assuming the leading and host vehicles were in the same ground plane. After both sensory data were obtained, they were synthesized and fused using Kalman filter, to generate a better estimation of headway distance. The performances of both sensors were assessed individually and the correlation between their measurements was evaluated by replotting radar measurements on the video stream. The results of individual sensors and Kalman filter were compared to investigate the optimization performance of the data fusion approach.This is a general guidance of headway distance estimation with a low cost radar and a monocular camera. With described general procedures, this paper can allow researchers to easily fuse radar and camera measurements to obtain optimized headway distance estimation. This paper can facilitate the development of a more realistic robotic driver that can mimic human driver behaviors.

Drag reduction technologies in aircraft design are the key enabler for reducing emissions and for sustainable growth of commercial aviation. Laminar wing technologies promise a significant benefit by drag reduction and are, therefore, under investigation in various European projects. However, of the established moveable concepts and high-lift systems thus far most do not cope with the requirements for natural laminar flow wings. To this aim, new leading edge high-lift systems have been the focus of research activities in the last 5 years. Such leading edge devices investigated in projects include a laminar flow-compatible Kruger flap (Schlipf (2011) Insect shielding Kruger—structural design for a laminar flow wing. In: DGLR Congress 2011, Bremen, pp 55–60) and the Droop Nose concept (Kintscher et al. Ground testof an enhanced adaptive droop nose device. In: European Congress on Computational Methods in Applied Sciences and Engineering, ECCOMAS 2016. ECCOMAS2016—VII European Congress on Computational Methods in Applied Sciences and Engineering, 5–10 June 2016, Crete Island, Greece; Kintscher et al. Low speed wind tunnel test of a morphing leading edge. In: AIDAA—Italian Association of Aeronautics and Astronautics XXII Conference, 09–12 Sept. 2013. Neapel, Italien) and these can be considered as alternatives to the conventional slat. Hybrid laminar flow concepts are also under investigation at several research institutes in Europe (Fischer. Stepless and sustainable research for the aircraft of tomorrow—from AFloNext to Clean Sky 2. In: 1st AFloNext Workshop Key Note Lecture No. 1, Delft, The Netherlands, 10 Sept 2015). Another challenge associated with laminar wings aside from the development of leading edge movables is the need to address the control of aerodynamic shocks and buffeting as laminar wings are sensitive to high flow speeds. Here, one possible method of decreasing the wave drag caused by the aerodynamic shock is through the use of shock control bumps (SCBs). The objective of SCBs is the conversion of a single strong shock into several smaller and weaker λ-shocks resulting in a drag benefit when deployed correctly. A particular desirable characteristic of SCBs is that they should be adaptable in position and height as the shock position changes with varying conditions such as speed, altitude, and angle of attack during the flight. However, as a fixed case, SCBs can also help to control laminar buffeting by fixing the shock into given positions at the SCBs location. In this paper, a structural concept for an adaptive shock control bump spoiler is presented. Based on a concept of a fixed bump SCB spoiler, a design for an adaptive spoiler with two conventional actuators is presented. Design drivers and interdependencies of important design parameters are discussed. The presented design is simple and aims for a high TRL without adding much complexity to the spoiler. It is robust and able to form a bump with a height of 0.6% chord length which position can be adapted in a range of 10% chord. This paper is a follow-up of a previous publication (Kintscher and Monner, SAE Tech Paper 10.4271/2017-01-2164, 2017) with extending the focus by a validation of computational results by experimental tests.

This paper is a preliminary step in the direction of the definition of a radically new wing concept that has been conceived to maximize the lift even at low speeds. It is expected to equip new aerial vehicle concepts that aim to compete against helicopters and tilt rotors. They aim achieving very good performance at very low speed (5 to 30 m/s) by mean of an innovative concept of morphing ducted-fan propelled wing that has been designed to maximize the lift force. This paper presents an effective bibliographic analysis of the problem that is a preliminary necessary step in the direction of the preliminary design of the wing. A preliminary CFD evaluation allows demonstrating that the claimed results are in line with the initial expectations. According to\ud the CFD, results it has been produced a preliminary energetic evaluation of the vehicle in a flying car configuration by EMIPS method. Even if the results are still preliminary, they allow evidencing a good energy efficiency of the vehicle against helicopters.

© 2017 SAE International. The goal of grid friendly charging is to avoid putting additional load on the electricity grid when it is heavily loaded already, and to reduce the cost of charging to the consumer. In a smart metering system, Day Ahead tariff (DA) prices are announced in advance for the next day. This information can be used for a simple optimization control, to select to charge at cheapest times. However, the balance of supply and demand is not fully known in advance and the Real-Time Prices (RTP) are therefore likely to be different at times. There is always a risk of a sudden price change, hence adding a stochastic element to the optimization in turn requiring dynamic control to achieve optimal time selection. A stochastic dynamic program (SDP) controller which takes this problem into account has been made and proven by simulation in a previous paper. Since there are differences between the DA and the RTP tariff, this paper proposes a (1) predictor to create an unbiased estimate of the RTP tariff based on available data. It uses a regression on historical data to find the best prediction of the expected price. Finally, a (2) case study based on data from the Illinois Electricity Grid prices is presented to validate the SDP controller over several years of data. The stochastic optimization uses the RTP prices effectively, getting very close to the globally optimal charging price. However, the predictor achieves only a slight reduction in prediction uncertainty with this data sate, and it has a negligible effect on cost. This means that DA prices can be used as a fair prediction of RTP charging cost here. The SDPM successfully reacts in the case study and leads to savings on charging costs over the years presented.

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.

This paper refers to the experimental results obtained using two different 4-cylinder diesel engines, with total displacement respectively equal to 1.9 L and 1.3 L, both equipped with an advanced common-rail system. An optically accessed prototype engine, having characteristics similar to the four-cylinder engine, is used to visualize the incylinder phenomena. Multidimensional simulations of the combustion and pollutants formation processes are performed, comparing the numerical predictions with the experimental data. By this way, integrating the 3D C.F.D. computations, the visualization techniques of the injection and combustion processes and the field measurements on the real engines, different settings of the multiple injection strategy have been analyzed.

The aim of this paper is to analyze the main concerns related to on-board hydrogen catalytic production of fuel cell electric vehicles, starting from different gaseous and liquid fuels. In particular, limits and potentialities of hydrocarbons and alcohols have been examined, considering steam reforming and partial oxidation reactions with reference to emission and efficiency implications. Preliminary results of an experimental investigation on steam reforming of natural gas and liquid hydrocarbons are reported. Furthermore, a mono-dimensional mathematical model of methane steam reformer based on first order kinetics has been developed to simulate the experimental results.

In the frame of the IEA-AMF, Annex XVII project "Real Impact of New Technologies for Heavy Duty Vehicles,' three state-of-the-art city bus technologies were evaluated for fuel consumption and emission in real city traffic and in a number of test cycles, both on engine and on vehicle level. One of the three buses was a natural gas bus with multi-point fuel injection, stoichiometric fuel control and three-way catalyst. Compared to the other tested technologies, this engine reached very low exhaust gas emissions. The paper will discuss the results obtained with the stoichiometric natural gas engine and compare the emissions in real traffic versus various engine test cycles, based on a number of influencing parameters. Concerning cycle characteristics, it was based on a number of influencing parameters. Concerning cycle characteristics, it was the distribution of the engine-operating points which had most effect on the exhaust gas emissions. Also the follow-up of acceleration, cruising and deceleration phases had a direct effect on catalyst functioning and thus also on the emissions. Apart from the cycle characteristics, some other parameters like intake air temperature, coolant temperature, lambda value, ignition timing or engine and component condition may also influence the emissions. The effect of coolant temperature variation on exhaust gas temperature and emissions was researched on engine test bench at Istituto Motori. It appeared that coolant temperature had no significant effect for this technology; most variations were related to small shifts in lambda and the condition of the three-way catalyst. Other factors like intake air temperature were not researched within the IEA-AMF project, but from previous experiences their influence was clearly proven.

This paper describes the project of a "small' single-cylinder direct injection diesel engine (300 cc). It is equipped with optical accesses to analyze the diesel combustion process employing the most recent optical diagnostic techniques. The injection system used is a second-generation common- rail system. The optical accesses are placed on the piston and on the cylinder wall.

In the present paper some results, obtained by the use of modern numerical C.F.D. tools, are presented. In particular, starting from the experimental characterization of a conventional design D.I. diesel engine, the empirical constants of the different submodels were tuned to obtain satisfactory results in some key test conditions. After that, in the same points of the engine performance map, the following parameters were systematically varied: fuel injection system design and operating conditions; intake swirl level; exhaust gas recirculation level. The influence of each parameter on combustion evolution is discussed and the most promising trend for the engine optimization is presented. Taking into account the model formulations limits, the results obtained suggest, from a theoretical point of view, that "common rail" equipped light duty diesel engines are suitable to meet the future European emission regulations. In particular the numerical analysis demonstrate that the emission potential of common rail engines is positioned between 2001 and 2005 emission limits. The last stage of emission regulations can be achieved only with further massive research activities.

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.

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.

The emergence of wide band gap devices has pushed the boundaries of power converter operations and high power density applications. It is desirable to operate a power inverter at high switching frequencies to reduce passive filter weight and at high temperature to reduce the cooling system requirement. The paper describes the design and test of a power electronic inverter that converts a fixed input DC voltage to a variable voltage variable frequency three phase output. The component selection and design were constrained such that the inverter can operate at an ambient temperature of 170°C. The design of the key functional components such as the gate drive, power module, controller and communication will be discussed in the paper. Test results for the inverter at high temperature will also be presented.

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

© Copyright 2016 SAE International. This work presents turbulent premixed combustion modeling in spark ignition engines using G-equation based turbulent combustion model. In present study, a turbulent flame speed expression proposed and validated in recent years by two co-authors of this paper is applied to the combustion simulation of spark ignition engines. This turbulent flame speed expression has no adjustable parameters and its constants are closely tied to the physics of scalar mixing at small scales. Based on this flame speed expression, a minor modification is introduced in this paper considering the fact that the turbulent flame speed changes to laminar flame speed if there is no turbulence. This modified turbulent flame speed expression is implemented into Ford in-house CFD code MESIM (multi-dimensional engine simulation), and is validated extensively. The predictions of the modified turbulent flame speed expression are compared to a wide range of experimental data of turbulent flame speed from various flame configurations and conditions, with the same values of the model constants. The quantitative comparisons are found to be very good with experimental data beyond the usually restricted range for existing turbulent flame speed models. Finally, applications of the new turbulent flame speed combustion model to the burn rate simulation of several spark ignition engines/operating conditions have been carried out. The simulated incylinder pressures and burn rates are compared with experimental data and good agreements are found for low tumble ratio engine operating conditions.

Cabin heating of current electric vehicle (EV) designs is typically provided using electrical energy from the traction battery, since waste heat is not available from an engine as in the case of a conventional automobile. In very cold climatic conditions, the power required for space heating of an EV can be of a similar magnitude to that required for propulsion of the vehicle. As a result, its driving range can be reduced very significantly during the winter season, which limits consumer acceptance of EVs and results in increased battery costs to achieve a minimum range while ensuring comfort to the EV driver. To minimize the range penalty associated with EV cabin heating, a novel climate control system that includes thermal energy storage from an advanced phase change material (PCM) has been designed for use in EVs and plug-in hybrid electric vehicles (PHEVs). The present paper focuses on the modeling and analysis of this electrical PCM-Assisted Thermal Heating System (ePATHS) and is a companion to the paper Design and Testing of a Thermal Storage System for Electric Vehicle Cabin Heating. A detailed heat transfer model was developed to simulate the PCM heat exchanger that is at the heart of the ePATHSmore » and was subsequently used to analyze and optimize its design. The results from this analysis were integrated into a MATLAB Simulink system model to simulate the fluid flow, pressure drop and heat transfer in all components of the ePATHS. The system model was then used to predict the performance of the climate control system in the vehicle and to evaluate control strategies needed to achieve the desired temperature control in the cabin. The analysis performed to design the ePATHS is described in detail and the system s predicted performance in a vehicle HVAC system is presented.« less

While a number of publications have addressed the high-level requirements of remanufacturing to ensure its commercial and environmental sustainability, considerably less attention has been given to the technical data and associated test strategies needed for any evidence-based decision as to whether a vehicle energy storage system should be remanufactured - extending its in-vehicle life, redeployed for second-life (such as domestic or grid storage) or decommissioned for recycling. The aim of this paper is to critically review the strategic requirements for data at the different stages of the battery value-chain that is pertinent to an Electric Vehicle (EV) battery remanufacturing strategy. Discussed within the paper is the derivation of a feasible remanufacturing test strategy for the vehicle battery system. Experimental results are presented that explore the trade-off between test accuracy as a function of key variables such as the ambient temperature at which the measurements are taken, the rate at which electrical current is used to charge/discharge the battery and the relaxation time allowed for the battery to equilibrate before the test is commenced. It is highlighted that the cost and environmental impact of remanufacturing EV battery systems relies heavily on the availability of a viable test strategy. Initial findings from the research are presented and testing on a 20 Ah pouch cell highlights that the variation in discharge capacity due to different temperatures can result in circa: 14% under-estimation. Also, waiting times between test periods (as defined within the best practice standards) can be reduced for different cells to improve testing time efficiency.

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.

This paper presents the experimental work carried out on single-lap joints fastened together with bolts and nuts to investigate the contribution of mode shapes, and the effect that bolt sizes has in dissipating energy in built-up structures. Five different bolt sizes are chosen to assemble five single-bolted single-lap joints using aluminum plates. An analogous monolithic solid piece carved from the same aluminum material is used to determine the material damping and compare it against the damping from bolted joints. The dynamic response of all structures is captured under free-free boundary conditions, and the common modes are analyzed to understand the contribution and primary source of damping in the same range of the sampling frequency. This investigation has revealed that the source of damping in the joints is heavily linked to the mode shapes of the structure and structural damping (also referred to as material damping) contributes more during specific mode shapes compared to the joint damping itself. The findings allow a more accurate implementation of energy loss in automotive structures which contain bolted joints, allowing an implementation of both material and joint loss factor, respectively.

Tight certification standards for new motor vehicles have always been the basestock for legislative efforts to control motor vehicle related air pollution. However, new additives need to be used when composing the formula for today's situation, where the relative contribution of new vehicles to the overall emissions is quickly diminishing and in-use performance is starting to play an increasingly important role.This paper outlines the general lay-out of the Finnish in-use control programme, which was started January 1, 1993. The choice of test procedure as well its initial verification are discussed. Determination and validation of the cut-points is also closely detailed. The main emphasis of the paper, however, lies in the practical experience gathered during the three-year planning and field testing phase that preceeded the introduction of the programme. Items that are typical for Finland, like cold ambient conditions, are more deeply discussed. Furthermore, some data from the results collected during the first 7 months of the programme is presented.Motor vehicles account a major share from many air polluting gaseous emissions. In addition, diesel powered vehicles emit fine particulates, which can have detrimental effects both on the environment as well as human health. Hence, many countries have introduced legislative efforts to control these emissions. Traditionally, these measures have mainly been targeted towards new vehicles, which have to be type approved according to relevant rules and regulations before they can enter the market.The progressive lowering of the standards world-wide has spurred the industry continuously to develop emission control technology. Mainly due to the widespread use of three-way-catalyst systems, the emission level of a new automobile has lowered so much, that its contribution to the overall emissions of the whole vehicle park is beginning to be almost neglible. Therefore, the lowering of standards for a new vehicle has lost most of its power to control total emissions. The performance of in-use vehicles has become overruling instead. Thus further reduction in emissions cannot be achieved without actions focused to in-use vehicles, as well.

Original Equipment Manufacturers (OEM’s) target lower probabilities of brake noise as part of quality requirements for disc brake systems. Since brake noise is significantly controlled by variations in environmental conditions or alterations of brake systems, the brake system needs “in build” robustness against those variations to minimize noise during its lifecycle. In the past, proof of brake noise quality was primarily based on tests. Currently, it is based on a combination of simulation and testing. Due to cost and time schedule constraints, improvement cycles late in the development process need to be reduced. That is only possible with an increase of Computer Aided Engineering (CAE) based robustness evaluation taking into account all relevant sources of variation which may have an influence on brake noise occurrence. Robustness evaluation is a methodology to investigate how input scatter affects response variation and helps to understand how causes connect to variation in responses. The paper will discuss the challenges for software tools, CAEmodelling and CAE-processes to successfully apply a CAE-based robustness evaluation for brake noise application in virtual prototyping. It should be noted that Dynardo is a general purpose engineering consultant for CAE-based robustness evaluation and is not specialized for dealing with brake squeal simulation problems. Thus the paper does not address what methods of CAE modeling are appropriate to reflect the underlying physics of brake squeal accurate enough. However, since simulation is used today to investigate brake squeal and simulation models are successfully validated against hardware tests, it can be stated that appropriate CAE-models are available and can be successfully used to perform robustness evaluation.

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.

The aim of this paper is to develop a new concept of unconventional airship based on morphing a lenticular shape while preserving the volumetric dimension. Lenticular shape is known to have relatively poor aerodynamic characteristics. It is also well known to have poor static and dynamic stability after the certain critical speed. The new shape presented in this paper is obtained by extending one and reducing the other direction of the original lenticular shape. The volume is kept constant through the morphing process. To improve the airship performance, four steps of morphing, starting from the lenticular shape, were obtained and compared in terms of aerodynamic characteristics, including drag, lift and pitching moment, and stability characteristics for two different operational scenarios. The comparison of the stability was carried out based on necessary deflection angle of the part of tail surface. The comparison results indicated that new shape concept possesses much better aerodynamic and stability characteristics and could be used for detailed optimisation studies.

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.

The heat generation rate of a lithium ion cell was estimated using a reversible heat generation rate equation. Because the equation is based on the energy conservation law, the influence of kinetically slow processes should be considered. In this analysis, the influence of kinetically slow processes is present but it is small within the domain of the test measurements. This approximation can be of significant usefulness for modeling the thermal response of single cells and multi-cell batteries. Introduction In a recent review article, the thermal issues associated with lithium ion batteries were outlined [1]. One of the issues that received attention was the need for improved modeling of the heat generation rate. An attempt was made to address this issue by analyzing a set of data published in a recent paper [2]. In that paper, a method of heat generation measurement for a prismatic battery was presented. In addition, the heat generation rate of a 20 Ah prismatic A123 LiFePO4 was measured during the discharge of that cell. The discharges were conducted in an operating domain of 0.25C to 3C rates and an operating temperature ranging from −10° C to 40° C. The data was presented in a series of plots that was amenable to digitalization for further analysis.

The maturity reached in the development of Unmanned Air Vehicles (UAVs) systems is making them more and more attractive for a vast number of civil missions. Clearly, the introduction of UAVs in the civil airspace requiring practical and effective regulation is one of the most critical issues being currently discussed. As several civil air authorities report in their regulations “Sense and Avoid” or “Detect and Avoid” capabilities are critical to the successful integration of UAV into the civil airspace. One possible approach to achieve this capability, specifically for operations beyond the Line-of-Sight, would be to equip air vehicles with a vision-based system using cameras to monitor the surrounding air space and to classify other air vehicles flying in close proximity. This paper presents an image-based application for the supervised classification of air vehicles. First, several vehicle images, taken from different points of view, are transformed using a descriptor of salient features as to build the five-class database used to train the classification algorithm. Then, the latter compares the descriptor of a vehicle image taken from a random point of view to records in the database. With a positive match, the vehicle will be assigned to one of the following classes: a) civil transport aircrafts, b) military aircrafts, c) general aviation aircrafts, d) helicopters, and e) airships/hot air balloons. The paper provides a possible layout for the algorithm implementation and presents the outcome of several tests performed to evaluate its efficiency and possible exploitation. Indications useful to further studies are presented to help future researches.

Ignition and flame inception are well recognised as affecting performance and stable operation of spark ignition engines. The very early stage of combustion is indeed the main source of cycle-to-cycle variability, in particular in gasoline direct injection (GDI) engines, where mixture formation may lead to non-homogenous air-to-fuel distributions, especially under some speed and load conditions. From a numerical perspective, 3D modelling of combustion within Reynolds Averaged Navier Stokes (RANS) approaches is not sufficient to provide reliable information about cyclic variability, unless proper changes in the initial conditions of the flow transport equations are considered. Combustion models based on the flamelet concept prove being particularly suitable for the simulation of the energy conversion process in internal combustion engines, due to their low computational cost. These models include a transport equation for the flame surface density, which needs proper initialization. A flame collocation is indeed to be properly made when starting the calculations, often just based on the user's skill and without resorting to any quantitative data derived from experiments. However, the way to define initial conditions for cyclic variability prediction is often based on just statistical considerations. This work aims at exploiting information derived from images collected in a single cylinder 4-stroke GDI engine to properly collocate the flame at the start of the combustion calculation. The considered engine is optically accessible through a wide fused-silica window fixed on the piston crown having a Bowditch design. Image processing methodologies are applied to evaluate local and integral luminous intensity, and flame morphology parameters. The collected data allows improving the numerical simulation and gaining hints about the main parameters defining the engine cyclic variability.

Low Carbon fuels will play a relevant role in the transportation sector contributing, over the powertrain technology progress, to mitigate global CO2 emissions. Compressed Natural Gas (CNG), mainly composed by methane, is one of the best candidate thanks to its chemical composition and to its wide diffusion and use. Blending Hydrogen in Natural Gas could represent a further step for a better CO2 footprint (considering renewable or biohydrogen) but also to optimize the combustion process, increasing the engine thermal efficiency and reducing pollutant formation. On the other hand, capability to automatically adapt the engine parameters to variable concentrations of Hydrogen in Natural Gas (in the range from 0% to 40% by volume) is a mandatory step to maintain engine performance, emissions and efficiency The activities described in this paper are part of a large collaborative project, “Biomethair”, funded by Regione Piemonte, where material specifications on gas tanks, valves, feeding lines, gas pressure regulator, engine pipes and injectors have been set and prototype components procured and implemented into the demonstrator vehicle to ensure safe operating conditions. In this paper a software algorithm is presented, able to provide, during normal car operation, real time estimates of methane-hydrogen composition, allowing the engine control system to adapt the control parameters engine. The algorithm is based on the innovative data-driven technology Direct Virtual Sensor, which allows to design the Virtual Sensor from the experimental data collected from a testing car, subject to suitable manoeuvres in different operational conditions, without requiring deep first principle modelling of the involved systems. The Virtual Sensor has been designed and implemented on the Electronic Control Unit of the demonstrator vehicle, giving suitably discretized estimates of Methane-Hydrogen composition, using measurements of engine revolution speed, of the lambda probe value and a variable from engine control unit. Experimental results of the Virtual Sensor performance evaluated in different operational conditions are presented.

Ice crystals ingested by a jet engine at high altitude can partially melt and then accrete within the forward stages of the compressor, potentially causing performance loss, damage and/or flameout. Recent research into this ice crystal icing (ICI) phenomenon conducted at the National Research Council of Canada suggests that the liquid water content vliq of an accretion significantly affects the accretion's susceptibility to erosion by ice crystals, and therefore accretion growth. This paper describes the development and application of an instrument for measuring vliq, potentially providing a method for correlating erosion behavior (e.g. as ductile or brittle) and properties. The instrument measures the complex admittance Y* of a mixed-phase deposit bridging a pair of electrodes, which is modeled as a resistor and capacitor in parallel, and calculates the deposit's relative permittivity εr from the capacitance. Experiments and electrostatic simulations were conducted to correlate εr as a function of vliq for vliq up to ∼40%, using calorimetry to determine vliq. These measurements were made at an excitation frequency of 2MHz, where the relative permittivities of ice and liquid water are insensitive to change of frequency. The paper also describes icing tests where the instrument was used to measure vliq as a function of freestream liquid-to-total water content (LWC/TWC) for two test articles, a cone and a forward-facing cup. The measurements show that vliq lies in the range 25-33% when LWC/TWC is in the range giving worst accretion (LWC/TWC∼10-20%). The instrument is also used to measure thickness growth rate for the cup., SAE 2015 International Conference on Icing of Aircraft, Engines, and Structures, June 22-25, 2015, Prague, Czech Republic

This paper will discuss the problem with successful predicting of product performance (reliability, quality, durability, safety, recalls, profit, life cycle cost, and other interconnected technical and economic components of performance). The best component for analysing the performance situation during service life, including predicting, is recalls, because, first, recall accumulates the safety , reliability, durability, quality, profit, and total economic situation. And second, there is open official and objective information about the number of recalls from Government (National Highway Trafic Safety Administration and others), as well as companies-producers. Therefore, for analyzing the situation with the product performance, including predicting, this paper considers the situation with recalls. First, it will demonstrate how dangerous the current situation is with recalls, safety, reliability, and durability, especially in automotive, including in the USA for last thirty years. Then it will be demonstrated that recalls directly connect with profit.

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.

After years of study and improvement, turbochargers in passenger cars now generally have very high efficiency. This is advantageous, but on the other hand, due to their high efficiency, only a small portion of the exhaust energy is needed for compressing the intake air, which means further utilization of waste heat is restricted. From this point of view, a turbo-compounding arrangement has significant advantage over a turbocharger in converting exhaust energy as it is immune to the upper power demand limit of the compressor. However, with the power turbine being located in series with the main turbine, power losses are incurred due to the higher back pressure which increases the pumping losses. This paper evaluates the effectiveness that the turbo-compounding arrangement has on a 2.0 litres gasoline engine and seeks to draw a conclusion on whether the produced power is sufficient to offset the increased pumping work. Furthermore, as mentioned above, the baseline engine model in this paper is not a heavy-duty diesel engine which is more appropriate to the turbo compounding mechanism for automotive application, but a small size gasoline engine. This paper also aims to explore a potential methodology for extending the operating range of the turbo compounding in light-duty petrol engine over its entire speed range under full load condition. The system models in this paper were built in GT-Power which is a one dimension (1-D) engine simulation code. Simulation results show that with the assistance of a variably driven supercharger, the output torque of the engine system is much larger (up to around 24%) at lower engine speeds. The fuel economy is also improved by up to about 8%.

In this paper, the advanced damage analysis of composite materials and structures made of continuous fibers embedded in a polymer matrix is addressed. The solution is based on the LMS Samtech Samcef finite element code, from Siemens PLM Software, which is now available in the Siemens NX CAE environment, with the specific focus of solving non-linear analysis problems for composites. Globally speaking, LMS Samtech Samcef is an implicit non-linear solver able to solve quasi-static and dynamic problems, with a comprehensive library of structural elements and kinematic joints. First, the sizing strategy based on the building block approach (pyramid of physical and virtual tests) is recalled. Applied for years in the aerospace industry, it is here extended to the automotive context. In this approach, the knowledge on the composite material and structure is built step by step from the coupon level up to the final full scale structure. In this paper, stages of the pyramid starting from the coupon level are considered, and the predictions obtained by numerical simulations are validated by test results. The non-linear analysis approach available in the LMS Samtech Samcef finite element code is then described. It is based on the continuum damage mechanics, and is used to study the progressive failure of composites in the plies and at their interface (delamination). The material models are described. The identification procedure for these damage models is also discussed: it is based on a very limited number of tests results at the coupon level. It is then shown how this information on the material behavior can be used at upper stages of the building block approach and so applied to larger scale structures and/or more complex load cases and different stacking sequences. The very good agreement obtained in this paper between simulation and test results on composite structures of increasing complexity tend to demonstrate that LMS Samtech Samcef can be used as a predictive numerical tool for the evaluation of the non-linear behavior of composites, including the progressive inter- and intra-laminar damage analysis.

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.

Because crash data does not always contain the necessary details of the role of forward lighting in crashes, this paper uses naturalistic driving data to assess the safety impacts of lighting in crashes. The paper shows how driving behavior and real time descriptions of crashes and near-misses might improve the understanding of how forward lighting can improve traffic safety.

Pedestrian throw distance can be used to evaluate vehicle impact speed for wrap or forward projection type pedestrian collisions. There have been multiple papers demonstrating relationships between the impact speed of a vehicle and the subsequent pedestrian throw distance. In the majority of instances, the scenarios evaluated focused on the central width of the vehicle impacting the pedestrian. However, based on investigated pedestrian collisions, the location where the pedestrian has engaged with the vehicle can and does significantly influence the throw distance (and projection) and subsequent impact speed analysis. PC-Crash was used to simulate multiple pedestrian impacts at varying speeds and vehicle impact locations, creating pedestrian throw distance impact speed contour plots. This paper presents the pedestrian throw distance impact speed contour plots for a range of nine vehicle types. The purpose of this paper is to illustrate that there is an effect on impacted pedestrians' throw distance and post impact direction due to both the vehicle shape and point of impact on the vehicle. However the effect is not yet validated by means of physical tests and further research is required.

Previous research on both small-scale and full-scale vehicles shows that base extensions are an effective method to increase the base pressure, enhancing pressure recovery and reducing the wake size. These extensions decrease drag at zero yaw, but show an even larger improvement at small yaw angles. In this paper, rear extensions are investigated on an SUV in the Volvo Cars Aerodynamic Wind Tunnel with focus on the wake flow and on the unsteady behavior of the surface pressures near the base perimeter. To increase the effect of the extensions on the wake flow, the investigated configurations have a closed upper- and lower grille (closed-cooling) and the underbody has been smoothed with additional panels. This paper aims to analyze differences in flow characteristics on the wake of an SUV at 0° and 2.5° yaw, caused by different sets of extensions attached to the base perimeter. Extensions with several lengths are investigated with and without a kick. Unsteady pressure sensors attached to the base perimeter of the vehicle are used. The fluctuations are examined for the reference vehicle and the vehicle with extensions for different freestream velocities and under a yaw angle ranging from 0° to 7.5° yaw. The current investigation indicates that the drag reduction obtained at 2.5° yaw with a “kick” mounted at the rear edge of the extensions have an effect on the size of the wake and enhance the pressure recovery behind the vehicle. The addition of the kick alters the wake distribution and changes the corresponding flow pattern with the largest effect under yaw conditions. For the unsteady surface pressure measurements, a technique based on Empirical Mode Decomposition (EMD) is applied that results in instantaneous frequencies of the signal. It gives the option of signal reconstruction limited to the frequency area of interest. A Proper Orthogonal Decomposition (POD) on the signals is also conducted, showing large variance in the area below the catwalk for the first two modes. To enhance the correlation, this paper investigates the combination of both mode decompositions, where the POD is applied to EMD-filtered signals.

Prediction of spray droplet temperature is routinely performed within automotive engineering CFD simulation. Important applications include fuel spray modelling for in-cylinder combustion studies and urea-water spray modelling for SCR aftertreatment studies. Transient droplet surface temperature strongly influences droplet and spray evaporation rate and subsequent system performance. In this paper, different droplet temperature models are presented and compared for both single droplet modelling and a single-hole Lagrangian spray CFD simulation in OpenFOAM. The aim is to determine the complexity of implementation of the models and their effect on prediction accuracy for droplet surface temperature, evaporation rate and lifetime. A non-ideal multi-component droplet evaporation model using UNIFAC and NRTL for activity coefficient calculation is used. Model gasoline fuels containing varying quantities of ethanol are studied at conditions appropriate to gasoline direct injection. Three droplet temperature models are compared: a lumped thermal model typically employed in CFD packages; an effective thermal conductivity model (ETC) using the full heat equation; and an ETC model tracking the surface and centre temperature only. For droplet simulations, discrepancies of up to 13% in calculated droplet lifetime are found between the lumped thermal model and the effective conductivity models. The greatest discrepancy in lifetime is observed at conditions and compositions where rapid liquid thermal transients are encountered. This effect is characterized for the first time using the wet-bulb temperature, initial liquid temperature and fuel ethanol content, to guide modellers to an appropriate temperature model for the level of accuracy desired. The effect of droplet temperature modelling in spray CFD simulation is smaller, as measured by maximum changes in spray penetration (2%), evaporation rate (2%) and Sauter Mean Diameter (1.2%). A non-uniform temperature model is required when significant transient temperature change is expected, near-nozzle spray is studied or sub-models such as droplet collision and break-up are not in use.

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 computational simulations utilized the Shaheen supercomputer at KAUST Supercomputing Laboratory. The scientific visualization was supported by the KAUST Visualization Core Laboratory. The authors thank Convergent Science Inc. for providing the CONVERGE license.

The paper is based upon work supported by Saudi Aramco Research and Development Center FUELCOM2 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 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

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.

Diesel sprays from an axially-disposed single-hole injector are studied under both non-vaporizing and vaporizing conditions in a constant-volume vessel. A hybrid shadowgraph/Mie scattering imaging set-up is used to acquire the liquid and vapor phases of the fuel distribution in a near-simultaneous visualization mode by a high-speed camera (40,000 fps). A diesel injector with k0 factor is used, having the exit-hole diameter of 0.1 mm and the ratio L/d =10. The studies are performed at the injection pressures of 70, 120, and 180 MPa, 25.37 kg/m3 ambient gas density, at the environment temperature of 373, 453 and 900 K. The instantaneous tip penetration of the liquid and vapor phases is extracted from the collected images and processed by a properly assessed software, under the various operating conditions. The AVL FIRE(TM) code is also used to simulate the spray dynamics. The model is validated on the ground of the collected experimental data. The results dependence upon the cell size of the computational mesh is preliminary discussed. Particular care is devoted to simulate the vaporizing conditions, where the performed combustion of an Acetylene/hydrogen mixture is properly simulated to well define not only the conditions of pressure and temperature within the vessel at the time of injection, but also the turbulent kinetic energy and dissipation rate, that allow correctly evaluating the relevant transport properties of mass, momentum and heat under turbulent flow conditions.

Direct use of straight vegetable oil based biofuels in diesel engines without trans-esterification can deliver more carbon reductions compared to its counterpart biodiesel. However, the use of high blends of straight vegetable oils especially used cooking oil based fuels in diesel engines needs to ensure compatible fuel economy with PD (Petroleum Diesel) and satisfactory operational performance. There are two ways to use high blends of SVO (Straight Vegetable Oil) in diesel engines: fixed blending ratio feeding to the engine and variable blending ratio feeding to the engine. This paper employed the latter using an on-board blending system-Bioltec system, which is capable of heating the vegetable oils and feeding the engine with neat PD or different blends of vegetable oils depending on engine load and temperature. A used cooking oil derived SVO type of biofuel, the C2G Ultra Biofuel (C2G: Convert to Green), which is a fully renewable fuel made as a diesel replacement from processed used cooking oil, used directly in diesel engines specifically modified for this purpose, has been investigated in this research. A series of real world driving tests were conducted on a 44 ton articulated truck. A dual fuel tank containing both PD and the C2G Ultra Biofuel was installed. The engine was started with PD and then switched to C2G Ultra Biofuel gradually. The vehicle was tested on either neat PD or blended fuel mode with different load (empty or fully loaded trailer). The fuel consumption and tailpipe emissions were measured. This paper focused on the fuel consumption and GHG reductions. The fuel consumption was determined by volumetric, mass and energy per km travelled and per ton of GVW. The results show that the fuel consumption for neat PD and blends was at the similar level and has a good inverse linear correlation with GVW. The substitution ratio of PD by the C2G Ultra Biofuel is 86∼91% and 74∼81% for hot start and cold start trips respectively. The GHG reductions by the C2G Ultra Biofuel are 85∼89% and 73∼78% for hot start and cold start trips respectively.

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.