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Viewing 1 to 30 of 15609
2016-06-15
Technical Paper
2016-01-1783
Oliver Engler
Mercedes-AMG GmbH specializes in unique, high-performance vehicles. The image of AMG as the successful performance brand of Mercedes-Benz is reflected in its impressive successes in the world of motorsport and its unique vehicles. One of these vehicles is the SLS AMG Coupé Electric Drive. After an elaborate series of tests as well as numerous test drives, we have created the SLS eSound which captures the exceptional dynamism of this unique super sports car with electric drive. Starting with a characteristic start-up sound, which rings out on pressing the "Power" button on the AMG DRIVE UNIT, the occupants can experience a tailor-made driving sound for each driving situation: incredibly dynamic when accelerating, subdued when cruising and as equally characteristic during recuperation. The sound is not only dependent on road speed, engine speed and load conditions, but also reflects the driving situation and the vehicle's operating state with a suitable driving noise.
2016-06-15
Technical Paper
2016-01-1805
Florian Zenger, Clemens Junger, Manfred Kaltenbacher, Stefan Becker
Abstract A low pressure axial fan for benchmarking numerical methods in the field of aerodynamics and aeroacoustics is presented. The generic fan for this benchmark is a typical fan to be used in commercial applications. The design procedure was according to the blade element theory for low solidity fans. A wide range of experimental data is available, including aerodynamic performance of the fan (fan characteristic curve), fluid mechanical quantities on the pressure and suction side from laser Doppler anemometer (LDA) measurements, wall pressure fluctuations in the gap region and sound characteristics on the suction side from sound power and microphone array measurements. The experimental setups are described in detail, as to ease reproducibility of measurement positions. This offers the opportunity of validating aerodynamic and aeroacoustic quantities, obtained from different numerical tools and procedures.
2016-06-15
Technical Paper
2016-01-1807
Olga Roditcheva, Lennart Carl Lofdahl, Simone Sebben, Pär Harling cEng, Holger Bernhardsson
Abstract This paper presents an experimental study of aeroacoustical sound sources generated by the turbulent flow around the side mirror of a Volvo V70. Measurements were carried out at the Volvo Cars aerodynamical wind tunnel (PVT) and at the aeroacoustical wind tunnel of Stuttgart University (FKFS). Several different measurement techniques were applied in both tunnels and the results were compared to each other. The configurations considered here were: side mirror with a cord and without the cord. The results discussed in this paper include intensity probe measurements in the flow around the side mirror, sound source localization with beamforming technique using a three-dimensional spherical array as well as standard measurements inside the car with an artificial head. This experimental study focused on understanding the differences between testing at the PVT and FKFS.
2016-06-15
Technical Paper
2016-01-1835
Albert Albers, Fabian Schille, Matthias Behrendt
Abstract In terms of customer requirements, driving comfort is an important evaluation criterion. Regarding hybrid electric vehicles (HEVs), maneuver-based measurements are necessary to analyze this comfort characteristic [1]. Such measurements can be performed on acoustic roller test benches, yielding time efficient and reproducible results. Due to full hybrid vehicles’ various operation modes, new noise and vibration phenomena can occur. The Noise Vibration Harshness (NVH) performance of such vehicles can be influenced by transient powertrain vibrations e.g. by the starting and stopping of the internal combustion engine in different driving conditions. The paper at hand shows a methodical procedure to measure and analyze the NVH of HEVs in different driving conditions.
2016-06-15
Journal Article
2016-01-1827
Giorgio Bartolozzi, Marco Danti, Andrea Camia, Davide Vige
Abstract The time to market in the automotive industry is constantly decreasing pushing the carmaker companies to increase the efforts in numerical simulations and to decrease the number of prototypes. In the NVH field, this time constraint reflects in moving the well-established finite element simulations towards the so called “full-vehicle simulations”. Specifically, the CAE techniques should be able to predict the complete behavior of the vehicles in mission conditions, so to reproduce some usual tests, such as the “coast down” test on different roads. The aim of this paper is to present a methodology to improve rolling noise simulations exploiting an integrated full-vehicle approach. An accurate modeling of all the subsystems is needed, with particular attention to the wheels and the suspension systems. Therefore, the paper firstly covers the modeling approach used to obtain the FE models of tires and suspension system.
2016-06-15
Technical Paper
2016-01-1848
Jean-Loup Christen, Mohamed Ichchou, Olivier Bareille, Bernard Troclet
Abstract The problem of noise transmission through a structure into a cavity appears in many practical applications, especially in the automotive, aeronautic and space industries. In the mean time, there is a trend towards an increasing use of composite materials to reduce the weight of the structures. Since these materials usually offer poor sound insulation properties, it is necessary to add noise control treatments. They usually involve poroelastic materials, such as foams or mineral wools, whose behaviour depends on many parameters. Some of these parameters may vary in rather broad ranges, either because of measurement uncertainties or because their values have not been fixed yet in the design process. In order to efficiently design sound protections, performing a sensitivity analysis can be interesting to identify which parameters have the most influence on the relevant vibroacoustic indicators and concentrate the design effort on them.
2016-04-05
Technical Paper
2016-01-1180
Trevor Crain, Thomas Gorgia, R. Jesse Alley
Abstract EcoCAR is North America's premier collegiate automotive engineering competition, challenging students with systems-level advanced powertrain design and integration. The EcoCAR Advanced Vehicle Technology Competition series is organized by Argonne National Laboratory, headline sponsored by the U.S. Department of Energy and General Motors, and sponsored by more than 30 industry and government leaders. In the last competition series, EcoCAR 2, fifteen university teams from across North America were challenged to reduce the environmental impact of a 2013 Chevrolet Malibu by redesigning the vehicle powertrain without compromising performance, safety, or consumer acceptability. This paper examines the results of the EcoCAR 2 competition’s emissions and energy consumption (E&EC) on-road test results for several prototype plug-in hybrid electric vehicles (PHEVs). The official results for each vehicle are presented along with brief descriptions of the hybrid architectures.
2016-04-05
Technical Paper
2016-01-1196
Yazhou Guo, Maji Luo, Jia Zou, Yunpeng Liu, Jianqiang Kang
Abstract Traction batteries are operated in severe working conditions of wide temperature range as the vehicles run in different seasons and regions, which effects battery performance deeply. Investigation on the effect of temperature under such circumstances on battery performance is very significant to promote the application of traction battery. In this paper, some tests are conducted on a ternary-material lithium-ion battery at various temperatures. The cycling performance and some significant parameters are evaluated at the whole temperature range, especially at the extreme temperatures (below -10°C or above 45°C). The results show that the battery performance becomes poor obviously at low temperatures, which is reflected in the decreased terminal voltage and the faded discharge capacity, and at too high temperatures (above 45°C), power and capacity also decrease, which happens in the later period of discharge process.
2016-04-05
Journal Article
2016-01-1191
Saher Al Shakhshir, Torsten Berning
Abstract Proton exchange membrane fuel cells (PEMFC’s) are currently being commercialized for various applications ranging from automotive (e.g. the Toyota Mirai) to stationary such as powering telecom backup units. In PEMFC’s, oxygen from air is internally combined with hydrogen to form water and produce electricity and waste heat. One critical technical problem of these fuel cells is still the water management: the proton exchange membrane in the center of these fuel cells has to be hydrated in order to stay proton-conductive while on the other hand excessive liquid water can lead to cell flooding and increased degradation rates. Clearly, a fundamental understanding of all aspects of water management in PEMFC is imperative. This includes the fuel cell water balance, i.e. which fraction of the product water leaves the fuel cell via the anode channels versus the cathode channel.
2016-04-05
Technical Paper
2016-01-1062
Ramachandran Ragupathy, K. Pothiraj, C. Chendil, T. Kumar Prasad, Prasanna Vasudevan
Abstract Hybrid powertrains generally involve adding an electric propulsion system to an existing internal combustion engine powertrain. Due to their reduced emissions, no reliance on public infrastructure and acceptable cost of ownership, hybrids are seen as a feasible intermediate step to deliver clean and affordable transportation for the masses. Such systems are immensely complex due to the number of interplaying systems and advanced control strategies used to deliver optimum performance under widely varying loads. Resonant torsional impacts arise out of the interactions due to rotational speed variations providing impulses at specific frequencies to the spinning inertias connected by members of finite stiffness. The effects, depending on the magnitude and duration of the impacts range from unacceptably harsh vibrations to catastrophic component failure.
2016-04-05
Technical Paper
2016-01-1084
Chendi Sun, Vinson Jia
Abstract With rigorous fuel consumption regulation and emission law implemented, accuracy requirement of design and measurement signal is increasing, it becomes more and more indispensable to consider the influence on pressure loss and flow behavior coming from the incrementally loaded dust on filter element of Air Intake System (AIS). Dust is composed of many different sizes of particles, and studies shows that these different sizes of particles have very distinct influence on pressure loss of filter elements, which makes dust a challenge to model in Computational Fluid Dynamics (CFD) simulation. In order to precisely simulate pressure loss behavior of dust loaded filter element, a methodology for 3-D CFD dust loading simulation is developed, where the influence of particles sizes on pressure loss of filter element are taken into consideration by introducing a pressure loss weighting factors.
2016-04-05
Technical Paper
2016-01-1033
Silvia Marelli, Giulio Marmorato, Massimo Capobianco, Jean-Maxime Boulanger
Abstract Turbocharging is playing today a fundamental role not only to improve automotive engine performance, but also to reduce fuel consumption and exhaust emissions for both Spark Ignition and diesel engines. Dedicated experimental investigations on turbochargers are therefore necessary in order to get a better understanding of its performance. The availability of experimental information on realistic turbine steady flow performance is an essential requirement to optimize engine-turbocharger matching calculations developed in simulation models. This aspect is more noticeable as regards turbine efficiency, since its swallowing capacity can be accurately evaluated through the measurement of mass flow rate, inlet temperature and pressure ratio across the machine. Actually, in the case of a turbocharger turbine, isentropic efficiency directly evaluated starting from measurement of thermodynamic parameters at the inlet and outlet sections can give significant errors.
2016-04-05
Technical Paper
2016-01-1622
Miroslav Mokry
Abstract Lagally’s theorem is used to evaluate the increments to aerodynamic forces on automotive models, tested in solid-wall wind tunnels. The strengths of the model-representing singularities, pre-requisite for the application of the theory, are obtained from experimental wall pressure data, using an influence matrix method. The technique is demonstrated on the drag force acting on full-size and half-size truck models, measured in the same test section.
2016-04-05
Technical Paper
2016-01-1518
Carolyn W. Roberts, Jacek Toczyski, Jack Cochran, Qi Zhang, Patrick Foltz, Bronislaw Gepner, Jason Kerrigan, Mark Clauser
Abstract Multiple laboratory dynamic test methods have been developed to evaluate vehicle crashworthiness in rollover crashes. However, dynamic test methods remove some of the characteristics of actual crashes in order to control testing variables. These simplifications to the test make it difficult to compare laboratory tests to crashes. One dynamic method for evaluating vehicle rollover crashworthiness is the Dynamic Rollover Test System (DRoTS), which simulates translational motion with a moving road surface and constrains the vehicle roll axis to a fixed plane within the laboratory. In this study, five DRoTS vehicle tests were performed and compared to a pair of unconstrained steering-induced rollover tests. The kinematic state of the unconstrained vehicles at the initiation of vehicle-to-ground contact was determined using instrumentation and touchdown parameters were matched in the DRoTS tests.
2016-04-05
Technical Paper
2016-01-1524
Feng Zhu, Binhui Jiang, Clifford C. Chou
Abstract This paper represents the development of a new design methodology based on data mining theory for decision making in vehicle crashworthy components (or parts) development. The new methodology allows exploring the big crash simulation dataset to discover the underlying complicated relationships between vehicle crash responses and design variables at multi-levels, and deriving design rules based on the whole vehicle safety requirements to make decisions towards the component and sub-component level design. The method to be developed will resolve the issue of existing design approaches for vehicle crashworthiness, i.e. limited information exploring capability from big datasets, which may hamper the decision making and lead to a nonoptimal design. A preliminary design case study is presented to demonstrate the performance of the new method. This method will have direct impacts on improving vehicle safety design and can readily be applied to other complex systems.
2016-04-05
Technical Paper
2016-01-1534
Rudolf Reichert, Pradeep Mohan, Dhafer Marzougui, Cing-Dao Kan, Daniel Brown
Abstract A detailed finite element model of a 2012 Toyota Camry was developed by reverse engineering. The model consists of 2.25M elements representing the geometry, thicknesses, material characteristics, and connections of relevant structural, suspension, and interior components of the mid-size sedan. This paper describes the level of detail of the simulation model, the validation process, and how it performs in various crash configurations, when compared to full scale test results. Under contract with the National Highway Traffic Safety Administration (NHTSA) and the Federal Highway Administration (FHWA), the Center for Collision Safety and Analysis (CCSA) team at the George Mason University has developed a fleet of vehicle models which has been made publicly available. The updated model presented is the latest finite element vehicle model with a high level of detail using state of the art modeling techniques.
2016-04-05
Technical Paper
2016-01-1517
Cole R. Young, David J. King, James V. Bertoch
Abstract The purpose of this study was to characterize the kinematics of four Chevrolet Tracker rollover tests and to determine their average and intermediate deceleration rates while traveling on concrete and dirt. Single vehicle rollover tests were performed using four 2001 Chevrolet Trackers fitted with six degree of freedom kinematic sensors. Tests were conducted using a rollover test device (RTD) in accordance with SAE J2114. The test dolly was modified (resting height of the vehicle wheels was raised) between tests 1, 2, and 3. The RTD was accelerated to 15.6 m/s (35 mph) and then decelerated rapidly by an energy absorbing crash cushion (EA) to cause the vehicle to launch and roll. The vehicles initially rolled on a smooth concrete surface and continued into loose dirt. This paper adds to the body of work identifying phases of constant deceleration during staged RTD tests and compares these phases to the overall deceleration rate.
2016-04-05
Technical Paper
2016-01-1549
Nicola Bartolini, Lorenzo Scappaticci, Francesco Castellani, Alberto Garinei
Knocking noise is a transient structural noise triggered by piston rod vibrations in the shock absorber that excite the vibration of chassis components. Piston rod vibrations can be caused by valve motion (opening and closing) and dry friction during stroke inversions. This study investigates shock absorber knocking noise in twin tube gas-filled automotive shock absorbers and its aim is to define an acceptance criterion for a sample check of the component. If, in fact, the damper comes from a large mass production, it may happen that small mounting differences lead to different behaviors that result in higher or lower levels of knocking noise. To achieve this goal, experimental tests were carried out using a hydraulic test bench; accelerometers were placed in proximity to the rebound valve and on the piston rod. The vibration phenomenon was then isolated through a post-processing analysis and a damped and unforced lumped mass model was used to characterize the vibration.
2016-04-05
Technical Paper
2016-01-1026
Silvia Marelli, Simone Gandolfi, Massimo Capobianco
Abstract Today turbocharging represents a key technology to reduce fuel consumption and exhaust emissions for both Spark Ignition and diesel engines, moreover improving performance. 1D models, generally employed to compute the engine-turbocharger matching conditions, can be optimized basing on certain information about turbine and compressor behavior. Because of difficulty in the correct evaluation of turbine isentropic efficiency with direct techniques, turbocharger turbine efficiency is generally referred to thermomechanical efficiency. To this aim, the possibility to accurately estimate power losses in turbocharger bearings can allow the assessment of the turbine isentropic efficiency starting from the thermomechanical one. In the paper, an experimental and theoretical study on turbocharger mechanical losses is presented. The proposed model, developed in the MATLAB environment, refers to radial and axial bearings.
2016-04-05
Technical Paper
2016-01-1355
Jeffrey R. Hodgkins, Walter Brophy, Thomas Gaydosh, Norimasa Kobayashi, Hiroo Yamaoka
Abstract Current vehicle acoustic performance prediction methods, CAE (computer aided engineering) or physical testing, have some difficulty predicting interior sound in the mid-frequency range (300 to 1000 Hz). It is in this frequency range where the overall acoustic performance becomes sensitive to not only the contributions of structure-borne sources, which can be studied using traditional finite element analysis (FEA) methods, but also the contribution of airborne noise sources which increase proportional to frequency. It is in this higher frequency range (>1000 Hz) that physical testing and statistical CAE methods are traditionally used for performance studies. This paper will discuss a study that was undertaken to test the capability of a finite element modeling method that can accurately simulate air-borne noise phenomena in the mid-frequency range.
2016-04-05
Technical Paper
2016-01-1607
David Soderblom, Per Elofsson, Ann Hyvärinen
Abstract The effect of blockage due to the presence of the wind tunnel walls has been known since the early days of wind tunnel testing. Today there are several blockage correction methods available for correcting the measured aerodynamic drag. Due to the shape of the test object, test conditions and wind tunnel dimensions the effect on the flow may be different for two cab variants. This will result in a difference in the drag delta between so-called open-road conditions and the wind tunnel. This makes it more difficult to evaluate the performance of two different test objects when they are both tested in a wind tunnel and simulated in CFD. A numerical study where two different cab shapes were compared in both open road condition, and in a digital wind tunnel environment was performed.
2016-04-05
Technical Paper
2016-01-1582
Dirk Wieser, Sabine Bonitz, Lennart Lofdahl, Alexander Broniewicz, Christian Nayeri, Christian Paschereit, Lars Larsson
Abstract Flow visualization techniques are widely used in aerodynamics to investigate the surface trace pattern. In this experimental investigation, the surface flow pattern over the rear end of a full-scale passenger car is studied using tufts. The movement of the tufts is recorded with a DSLR still camera, which continuously takes pictures. A novel and efficient tuft image processing algorithm has been developed to extract the tuft orientations in each image. This allows the extraction of the mean tuft angle and other such statistics. From the extracted tuft angles, streamline plots are created to identify points of interest, such as saddle points as well as separation and reattachment lines. Furthermore, the information about the tuft orientation in each time step allows studying steady and unsteady flow phenomena. Hence, the tuft image processing algorithm provides more detailed information about the surface flow than the traditional tuft method.
2016-04-05
Technical Paper
2016-01-1581
Felix Wittmeier, Armin Michelbach, Jochen Wiedemann, Victor Senft
Abstract With its recent wind tunnel upgrade, FKFS installed the first interchangeable three-belt / five-belt-system (FKFS first®) in a full scale automotive wind tunnel. With the five-belt system, which today is a state-of-the-art ground simulation technique, the system is ideally suited for production vehicle development work. The five-belt system offers high flexibility, quick access to the underfloor and vehicle fixation, and setting the vehicle’s ride height by the restraint device. The first results of the five-belt system have already been published in SAE 2015-01-1557 [1]. The three-belt system on the other hand, offers a much more sophisticated ground simulation technique which is necessary especially for sports and racing cars. For such vehicles with very low ground clearances, it is important to have a more accurate ground simulation, in order to capture the same aerodynamic modes of action and response as on the road.
2016-04-05
Technical Paper
2016-01-1594
Petter Ekman, Roland Gardhagen, Torbjorn Virdung, Matts Karlsson
Abstract Considerable amounts of the everyday goods transports are done using light trucks. In the last ten years (2005-2015), the number of light trucks has increased by 33 % in Sweden. The majority of these light trucks are fitted with a swap body and encounter the same problem as many other truck configurations, namely that several different manufacturers contribute to the final shape of the vehicle. Due to this, the aerodynamics of the final vehicle is often not fully considered. Hence there appears to be room for improving the aerodynamic performance. In this study the flow around a swap body fitted to a light truck has been investigated using Computational Fluid Dynamics. The focus has been on improving the shape of the swap body in order to reduce both the aerodynamic drag and fuel consumption, while still keeping it usable for daily operations.
2016-04-05
Technical Paper
2016-01-0115
Dev S. Kochhar, Hong Zhao, Paul Watta, Yi Murphey
Abstract Lane change events can be a source of traffic accidents; drivers can make improper lane changes for many reasons. In this paper we present a comprehensive study of a passive method of predicting lane changes based on three physiological signals: electrocardiogram (ECG), respiration signals, and galvanic skin response (GSR). Specifically, we discuss methods for feature selection, feature reduction, classification, and post processing techniques for reliable lane change prediction. Data were recorded for on-road driving for several drivers. Results show that the average accuracy of a single driver test was approx. 70%. It was greater than the accuracy for each cross-driver test. Also, prediction for younger drivers was better.
2016-04-05
Technical Paper
2016-01-0120
Libo Huang, Huanlei Chen, Zhuoping Yu, Jie Bai
Abstract Automotive radar is the most important component in the autonomous driving system, which detects the obstacles, vehicles and pedestrians around with acceptable cost. The target tracking is one of the key functions in the automotive radar which estimates the position and speed of the targets having regarding to the measurement inaccuracy and interferences. Modern automotive radar requires a multi-target tracking algorithm, as in the radar field of view hundreds of targets can present. In practice, the automotive radar faces very complicated and fast-changing road conditions, for example tunnels and curved roads. The targets’ unpredictable movements and the reflections of the electromagnetic wave from the tunnel walls and the roads will make the multi-target tracking a difficult task. Such situation may last several seconds so that the continuous tracks of the targets cannot be maintained and the tracks are dropped mistakenly.
2016-04-05
Technical Paper
2016-01-0123
Mostafa Anwar Taie, Mohamed ElHelw
Abstract The evaluation of Advanced Driver Assistance Systems (ADAS including driver assistance and active safety) has increasing interest from authorities, industry and academia. AsPeCSS active safety project concludes that good results in a laboratory test for active safety system design does not necessarily equate to an effective system in real traffic conditions. Moreover, many ADAS assessment projects and standards require physical testing on test tracks (dummy vehicles, pedestrian mannequins…), which are expensive and limit testing capabilities. This research presents a conceptual framework for on-board evaluation (OBE) of ADAS, which can be used as a cost effective evaluation in real-life traffic conditions. OBE shall monitor, record, analyze and report both internal behavior and external environment (external objects list and video stream) of ADAS under evaluation (ADASUE).
2016-04-05
Technical Paper
2016-01-0139
Andreas Himmler, Klaus Lamberg, Tino Schulze, Jann-Eve Stavesand
Abstract Increasing productivity along the development and verification process of safety-related projects is an important aspect in today’s technological developments, which need to be ever more efficient. The increase of productivity can be achieved by improving the usability of software tools and decreasing the effort of qualifying the software tool for a safety-related project. For safety-critical systems, the output of software tools has to be verified in order to ensure the tools’ suitability for safety-relevant applications. Verification is particularly important for test automation tools that are used to run hardware-in-the-loop (HIL) tests of safety-related software automatically 24/7. This qualification of software tools requires advanced knowledge and effort. This problem can be solved if a tool is suitable for developing safety-related software. This paper explains how this can be achieved for a COTS test automation tool.
2016-04-05
Technical Paper
2016-01-0232
Zhijia Yang, Edward Winward, Song Lan, Richard Stobart
Abstract Two identical commercial Thermo-Electric Modules (TEMs) were assembled on a plate type heat exchanger to form a Thermoelectric Generator (TEG) unit in this study. This unit was tested on the Exhaust Gas Recirculation (EGR) flow path of a test engine. The data collected from the test was used to develop and validate a steady state, zero dimensional numerical model of the TEG. Using this model and the EGR path flow conditions from a 30% torque Non-Road Transient Cycle (NRTC) engine test, an optimization of the number of TEM units in this TEG device was conducted. The reduction in fuel consumption during the transient test cycle was estimated based on the engine instantaneous Brake Specific Fuel Consumption (BSFC). The perfect conversion of TEG recovered electrical energy to engine shaft mechanical energy was assumed. Simulations were performed for a single TEG unit (i.e. 2 TEMs) to up to 50 TEG units (i.e. 100 TEMs).
2016-04-05
Technical Paper
2016-01-0235
Serenat Karagoz, Murat Karaer, Nurettin Ali Dasdemir
Abstract In this paper a combined energy recovery system is suggested for engine test facilities. System consists of two semi loops which are being active according to the temperature of the air feeded to the test cell. Winter and summer semi loops are introduced with the system requirements and equipments. Working principle of both semi-loops and components with the selection critera are explained. Also cost and benefit analysis is given in detail. It is evident that hot exhaust gases of the combustion processes is the main source that a large amount of energy wastes through it. Researchers confirm that more than 30% - 40% of fuel energy in the internal combustion engines wastes from the exhaust and just 12% -25% of the fuel energy converts to useful work. In the other hand, statistics show that producing numbers of the internal combustion engines growth very fast and the concern of decreasing the fossil fuels will be appeared.
Viewing 1 to 30 of 15609