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Viewing 1 to 30 of 15610
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
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.
2016-06-15
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
2016-01-1835
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.
2016-04-05
Technical Paper
2016-01-0899
Takashi Hoshino, Farrukh Qureshi, Nicholas Virostko, Elizabeth Schiferl, Ananda Gajanayake, Motoji Hiroki, Tomoya Higuchi, Keita Ishizaki
The growing need for improved fuel economy is a global challenge due to continuously tightening environmental regulations targeting lower CO2 emission levels via reduced fuel consumption in vehicles. In order to reach these fuel efficiency targets, it necessitates improvements in hardware by applying advanced technologies in design, materials and surface treatments etc., as well as matching lubricant formulations with appropriate chemistry in. Axle lubricants have a significant impact on fuel economy. Importantly, they can be tailored to deliver maximum operation efficiency over either specific or wide ranges of operating conditions. The proper lubricant technology with well-balanced chemistries can simultaneously realize both fuel economy and hardware protection, which are commonly known to be having a trade-off relationship.
2016-04-05
Technical Paper
2016-01-0766
Tongyang Gao, Marko Jeftic, Geraint Bryden, Graham Reader, Jimi Tjong, Ming Zheng
Abstract The control of nitrogen oxide and smoke emissions in diesel engines has been one of the key researches in both the academia and industry. Nitrogen oxides can be effectively suppressed by the use of exhaust gas recirculation (EGR). However, the introduction of inert exhaust gas into the engine intake is often associated with high smoke emissions. To overcome these issues there have been a number of proposed strategies, one of the more promising being the use of low temperature combustion enabled with heavy EGR. This has the potential to achieve simultaneously low emissions of nitrogen oxide and smoke. However, a quantitative way to identify the transition zone between high temperature combustion and low temperature combustion has still not been fully explored. The combustion becomes even more complicated when ethanol fuel is used as a partial substitution for diesel fuel.
2016-04-05
Technical Paper
2016-01-0197
Ravi Ranjan, Kaushal Kumar Jha, Lakshmaiah Brahmasani, Parvej Khan
Abstract The traditional approach of engine thermal behavior of engine during startup has largely been dependent on experimental studies and high fidelity simulations like CFD. However, these techniques require considerable effort, cost and time. The low fidelity simulations validated with experimental results are becoming more popular due to their ease in handling the several parameters such as cost effectiveness and quick predictive results. A four point mass model of engine thermal behavior during cold start has been developed to study the engine warm up temperature behavior. The four point mass model considers the lumped mass of coolant, mass of engine directly associated with the coolant, mass of engine oil and mass of engine directly associated with the engine oil. The advantage of four point model is to predict the coolant temperature as well as lubricant temperature during the transient warm up cycle of the engine.
2016-04-05
Journal Article
2016-01-0192
Alaa El-Sharkawy, Ahmed Uddin
Abstract Engine mount is one of the temperature sensitive components in the vehicle under-hood. Due to increasing requirements for improved fuel economy, the under-hood thermal management has become very challenging in recent years. In order to study the effects of material thermal degradation on engine mount performance and durability; it is required to estimate the temperature of engine mount rubber during various driving conditions. The effect of temperature on physical properties of natural rubber can then be evaluated and the life of engine mount can be estimated. In this paper, a bench test is conducted where the engine mount is exposed to a step change in the environment around it, and the temperature of the rubber section is recorded at several points till a steady state temperature is reached. A time response curve is generated, from which a time constant is determined.
2016-04-05
Technical Paper
2016-01-0201
Armin Traussnig, Wilko Jansen, Heinz Petutschnig, Sepp Steiner, Petra Gruen
Abstract In order to meet current and future emission and CO2 targets, an efficient vehicle thermal management system is one of the key factors in conventional as well as in electrified powertrains. Global vehicle simulation is already a well-established tool to support the vehicle development process. In contrast to conventional vehicles, electrified powertrains offer an additional challenge to the thermal conditioning: the durability of E-components is not only influenced by temperature peaks but also by the duration and amplitude of temperature swings as well as temperature gradients within the components during their lifetime. Keeping all components always at the preferred lowest temperature level to avoid ageing under any conditions (driving, parking, etc.) will result in very high energy consumption which is in contradiction to the efficiency targets.
2016-04-05
Technical Paper
2016-01-0293
Jaspreet Singh, Vishnu Agrawal
Abstract The paper expresses an important issue of optimum selection of a supercharger for a given application from the global market in the presence of a variety of superchargers available commercially off the shelf (COTS). Coding scheme suggested is based on developing an attribute based scheme for all superchargers available off the shelf. N-digit coding scheme provides in-depth understanding of all the attributes to be considered by the customers, designers, engineers and engineers of the industry for further improvement. We also aim to create exhaustive database of superchargers along with their attributes. The paper adopts a MADM-TOPSIS (Multiple Attribute Decision Making -Technique for Order of Preference by Similarity to Ideal Solution) technique and graphical methods that are being used widely in different disciplines and are published. The method ensures that the optimum supercharger is closest to the hypothetically best solution and farthest from the worst solution.
2016-04-05
Technical Paper
2016-01-0320
Tejas Janardan Sarang, Mandar Tendolkar, Sivakumar Balakrishnan, Gurudatta Purandare
Abstract In the automotive industry, multiple prototypes are used for vehicle development purposes. These prototypes are typically put through rigorous testing, both under accelerated and real world conditions, to ensure that all the problems related to design, manufacturing, process etc. are identified and solved before it reaches the hands of the customer. One of the challenges faced in testing, is the low repeatability of the real world tests. This may be predominantly due to changes in the test conditions over a period of time like road, traffic, climate etc. Estimating the repeatability of a real world test has been difficult due to the complex and multiple parameters that are usually involved in a vehicle level test and the time correlation between different runs of a real world test does not exist. In such a scenario, the popular and the well-known univariate correlation methods do not yield the best results.
2016-04-05
Technical Paper
2016-01-0323
Sashank Mani Vedula, Nabal Kishore Pandey, KumarPrasad Tellikepalli, Satish Thimmalapura
Abstract OEMs these days are focusing on front loading the activities to Virtual Test Environment (VTE) based development owing to high development cost and complexity in achieving repeatability during testing phase of vehicle development,. This process not only helps in reducing the cost and time but also helps in increasing the maturity and confidence level of the developed system before actual prototype is built. In the past, extensive research has happened for increasing the fidelity of VTE by improving plant model efficacy which involves powertrain and other vehicle systems. On the other hand, improving the precision of driver model which is one of the most complex nonlinear systems of virtual environment still remains a challenge. It is apparent that various drivers show different behavior in real world for a given drive profile. While modelling a driver for a VTE, the real world driver attributes are seldom considered.
2016-04-05
Journal Article
2016-01-0371
Wenkai Li, Carlos Engler-Pinto, Haitao Cui, Weidong Wen, Xuming Su
Abstract In this paper, fatigue tests on a cast aluminum alloy (AS7GU-T64) were performed under different frequencies and humidity levels. Tests conducted under conventional frequency in laboratory air have been compared to tests conducted under ultrasonic frequency in dry air, saturated humidity and in distilled water. It was observed that the highest and lowest fatigue lives correspond to ultrasonic fatigue tests in dry air and in distilled water, respectively. Unlike specimens tested at conventional frequency, all of the specimens tested at ultrasonic frequency presented a large amount of slip facets on the fatigue crack propagation fracture surface.
2016-04-05
Journal Article
2016-01-0373
Mohammadreza Eftekhari, Ali Fatemi, Abolhassan Khosrovaneh
Abstract An experimental study was conducted to evaluate the variable amplitude fatigue behavior of a neat polymer (polypropylene impact co-polymer) and a polymer composite made of polybutylene terephthalate (PBT) with 30 wt% short glass fibers. Fatigue tests were conducted on un-notched and notched specimens at room temperatures. Plate-type specimens were prepared in the transverse direction with respect to the injection mold flow direction and a circular hole was drilled in the center of notched specimens. Two-step loadings (high-low and low-high) tests at two damage ratio of 0.2 and 0.5 at stress ratios of R = 0.1 and -1 were conducted to investigate load sequence effects and prediction accuracy of the linear damage rule. Different behaviors were observed for unreinforced and short glass fiber reinforced polymers under the two-step loading tests.
2016-04-05
Technical Paper
2016-01-0418
Xin Xie, Danielle Zeng, Junrui Li, Jeffrey Dahl, Qiancheng Zhao, Lianxiang Yang
Abstract Polymer plastics are widely used in automotive light weight design. Tensile tests are generally used to obtain material stress-strain curves. Due to the natural of the plastic materials, it could be elongated more than several hundred percent of its original length before breaking. Digital Image Correlation (DIC) Analysis is a precise, full field, optical measurement method. It has been accepted as a practical in-field testing method by the industry. However, with the traditional single-camera or dual-camera DIC system, it is nearly impossible to measure the extreme large strain. This paper introduces a unique experimental procedure for large elongation measurement. By utilization of quad-camera DIC system and data stitch technique, the strain history for plastic material under hundreds percent of elongation can be measured. With a quad-camera DIC system, the correlation was conducted between two adjacent cameras.
2016-04-05
Technical Paper
2016-01-0417
Wan Xu, Xinfeng Shi, Tian Bai, Guobiao Yang, Lianxiang Yang, Changqing Du, Dajun Zhou, Yongjun Zhou
Abstract In Aluminum Alloy, AA, sheet metal forming, the through thickness cracking at the edge of cut out is one of the major fracture modes. In order to prevent the edge cracking in production forming process, practical edge stretch limit criteria are needed for virtual forming prediction and early stamping trial evaluations. This paper proposes new methods for determining the edge stretching limit of the sheet coupons, with and without pre-stretching, based on the Digital Image Correlation (DIC) technique. A numbers of sets of notch-shaped smaller coupons with three different pre-stretching conditions (near 5%, 10% and fractured) are cut from the prestretched large specimens. Then the notch-shaped smaller coupons are stretched by uniaxial tension up to through edge cracking observed. A dual-camera 3D-DIC system is utilized to measure both coupon face strain and thickness strain in the notch area at the same time.
2016-04-05
Technical Paper
2016-01-0419
Whitney Poling, Vesna Savic, Louis Hector, Anil Sachdev, Xiaohua Hu, Arun Devaraj, Fadi Abu-Farha
Abstract The strain-induced diffusionless shear transformation of retained austenite to martensite during straining of transformation induced plasticity (TRIP) assisted steels increases strain hardening and delays necking and fracture leading to exceptional ductility and strength, which are attractive for automotive applications. A novel technique that provides the retained austenite volume fraction variation with strain with improved precision is presented. Digital images of the gauge section of tensile specimens were first recorded up to selected plastic strains with a stereo digital image correlation (DIC) system. The austenite volume fraction was measured by synchrotron X-ray diffraction from small squares cut from the gage section. Strain fields in the squares were then computed by localizing the strain measurement to the corresponding region of a given square during DIC post-processing of the images recorded during tensile testing.
2016-04-05
Technical Paper
2016-01-0429
Paul Augustine, Timothy Hunter, Nathan Sievers, Xiaoru Guo
Abstract The performance of a structural design significantly depends upon the assumptions made on input load. In order to estimate the input load, during the design and development stage of the suspension assembly of a BAJA car, designers and analysts invest immense amount of time and effort to formulate the mathematical model of the design. These theoretical formulations may include idealization errors which can affect the performance of the car as a final product. Due to the errors associated with the assumption of design load, several components might have more weight or may have less strength than needed. This discrepancy between the assumed input load (lab or theoretical studies) and the actual load from the environment can be eliminated by performing a real life testing process using load recovery methodology. Commercial load cells exist in industry to give engineers insight to understanding the complex real world loading of their structures.
2016-04-05
Technical Paper
2016-01-0405
Fupin Wei, Li Xu, Chen Cao, Youmei Zhao
Crash Test Dummies are the very important tools to evaluate the vehicle safety performance. In order to ensure the dummy performance during the crash tests, the dummy components need to be certificated. In the neck certification procedure, the head angle is the most important parameter, which is the head rotation respect to the neck base. To get the head angle, couples of rotary potentiometers should be mounted either on the calibration fixture or on the dummy head. The rotation is then calculated from those potentiometer readings. There are two potentiometers mounted in the Hybrid III family dummies, while three potentiometers mounted in ES2, ES-2re, SID-IIs, and WorldSid 50th dummies. In the certification, maximum head angle and time occurred should be within certain ranges in the Hybrid III family dummies while for the ES2 and WorldSid 50th dummies, not only the maximum head angle, but also the other angles and their timings should meet the requirements.
2016-04-05
Technical Paper
2016-01-1277
Monis Alam, Ashish Jaiswal, Jatin Agarwal, Ketan Yadav, Naveen Kumar
Abstract Gasoline has been the major fuel in transportation, its good calorific value and high volatility have made it suitable for use in different injection methods. The drastic increase in use of carbon based fuels has led to increase in harmful emissions, thus resulting in implementation of stricter emissions norms. These harmful emissions include carbon monoxide and NOx. To meet the new norms and reduce the harmful emissions, better techniques have to be implemented to achieve better combustion of gasoline and reduce the amount of carbon monoxide in the exhaust. One such way of doing this is by enriching gasoline with hydrogen. Due to its low activation energy and high calorific value, the high energy released from hydrogen can be used to achieve complete combustion of gasoline fuel. However, there are certain drawbacks to the use of hydrogen in spark ignition engine, knocking and overheating of engine parts being the major problems.
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
2016-01-1196
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
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
2016-01-1300
Jacob Milhorn, Vincent Rovedatti, Richard DeJong, Gordon Ebbitt
Abstract Road tests on a pickup truck have been conducted to determine the acoustic loads on the back panel surfaces of the vehicle. Surface mounted pressure transducers arrays are used to measure both the turbulent flow pressures and the acoustic pressures. These measurements are used to determine the spatial excitation parameters used in an SEA model of the transmission loss through the back panel surfaces. Comparisons are made between tests on different road surfaces and at different speeds to identify the relative contributions of acoustic and wind noise.
2016-04-05
Journal Article
2016-01-1310
Yitian Zhang, David W. Herrin, T. Wu, Xin Hua
Abstract Prior research on assessing multiple inlet and outlet mufflers is limited, and only recently have researchers begun to consider suitable metrics for multiple inlet and outlet mufflers. In this paper, transmission loss and insertion loss are defined for multiple inlet and outlet mufflers using a superposition method that can be extended to any m-inlet n-outlet muffler. Transmission loss is determined assuming that the sources and terminations are anechoic. On the other hand, insertion loss considers reflections. For both metrics, the amplitude and phase relationship between the sources should be known a priori. This paper explains both metrics, and measurement of transmission and insertion loss are demonstrated for a 2-inlet 2-outlet muffler with good agreement.
2016-04-05
Technical Paper
2016-01-1313
Brian Pinkelman, Woo-Keun Song
Abstract Most methods of vibration analysis focus on measuring the level of vibration. Some methods like ISO-2631 weigh vibration level based on human sensitivity of location, direction, and frequency. Sound can be similarly measured by sound pressure level in dB. It may also be weighted to human frequency sensitivity such as dBA but sound and noise analysis has progressed to measure sound quality. The characteristic and the nature of the sound is studied; for example equal or near equal sound levels can provide different experiences to the listener. Such is the question for vibration; can vibration quality be assessed just as sound quality is assessed? Early on in our studies, vibration sensory experts found a difference in 4 seats yet no objective measurement of vibration level could reliably confirm the sensory experience. Still these particular experiences correlated to certain verbal descriptors including smoothness/roughness.
2016-04-05
Technical Paper
2016-01-0833
Lei Meng, Yuqiang Li, Karthik Nithyanandan, Timothy Lee, Chunnian Zeng, Chia-Fon Lee
Abstract To face the challenges of fossil fuel shortage and air pollution problems, there is growing interest in the potential usage of alternative fuels such as bio-ethanol and bio-butanol in internal combustion engines. The literature shows that the acetone in the Acetone-Butanol-Ethanol (ABE) blends plays an important part in improving the combustion performance and emissions, owing to its higher volatility. In order to study the effects of acetone addition into commercial gasoline, this study focuses on the differences in combustion, performance and emission characteristics of a port-injection spark-ignition engine fueled with pure gasoline (G100), ethanol-containing gasoline (E30) and acetone-ethanol-gasoline blends (AE30 at A:E volumetric ratio of 3:1). The tests were conducted at 1200RPM with the default calibration (for gasoline), at 3 bar and 5 bar BMEP under various equivalence ratios.
2016-04-05
Technical Paper
2016-01-0796
Ashish Shah, Per Tunestal, Bengt Johansson
Abstract This article presents a study related to application of pre-chamber ignition system in heavy duty natural gas engine which, as previously shown by the authors, can extend the limit of fuel-lean combustion and hence improve fuel efficiency and reduce emissions. A previous study about the effect of pre-chamber volume and nozzle diameter on a single cylinder 2 liter truck-size engine resulted in recommendations for optimal pre-chamber geometry settings. The current study is to determine the dependency of those settings on the engine size. For this study, experiments are performed on a single cylinder 9 liter large bore marine engine with similar pre-chamber geometry and a test matrix of similar and scaled pre-chamber volume and nozzle diameter settings. The effect of these variations on main chamber ignition and the following combustion is studied to understand the scalability aspects of pre-chamber ignition. Indicated efficiency and engine-out emission data is also presented.
Viewing 1 to 30 of 15610