Criteria

Text:
Sector:
Display:

Results

Viewing 181 to 210 of 86934
2018-04-03
Technical Paper
2018-01-1411
WENKAI Li, Carlos Engler-Pinto, Xuming Su, Ziang li
Ultrasonic fatigue tests (testing frequency around 20kHz) have been conducted on A356 aluminum alloys with different Cu contents and AS7GU aluminum alloy. Tests were performed in dry air and submerged in water. The effect of Cu percentage was investigated, it was concluded that under the same Cu percentage, the material strength may be the key factor influencing the environment humidity effect in ultrasonic fatigue testing.
2018-04-03
Technical Paper
2018-01-1412
Paul Dekraker, Daniel Barba, Andrew Moskalik, Karla Butters
The Environmental Protection Agency (EPA) has collected a variety of engine and vehicle test data for use in assessing the effectiveness of new automotive technologies in meeting greenhouse gas (GHG) and criteria emission standards, along with monitoring their behavior in real world operation. EPA’s Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) tool was created to estimate GHG emissions from vehicles using various combinations of advanced technologies and has been refined using data from tests conducted at EPA’s National Vehicle and Fuel Emissions Laboratory. This paper describes EPA’s process of constructing full engine maps from engine dynamometer test data for use in ALPHA or other full vehicle simulation models. The paper reviews how EPA uses available data, both steady state and transient, to characterize different operating conditions, and combining them to construct a map suitable for simulation.
2018-04-03
Technical Paper
2018-01-1409
Zhigang Wei, Limin Luo, Ameya Basutkar, Hong Tae Kang
Corrosion and Corrosion-fatigue (CF) have long been recognized as the major degradation and failure mechanisms of engineering materials under combined mechanical loading and corrosive environments. How to model and characterize these failure phenomena and how to screen, rank, and select materials in corrosion and corrosion-fatigue resistance is a significant challenge in many engineering applications. In this paper, simple parameters for characterizing corrosion resistance of materials are proposed. For corrosion-fatigue, the mathematical structure of a superposition-theory based corrosion-fatigue model is investigated and possible closed-form and approximate solutions are sought. Based on the model and the associated solutions and test results, ranking of the materials in corrosion, fatigue, corrosion-fatigue, and related material design are discussed.
2018-04-03
Technical Paper
2018-01-1410
Wei-Jen Lai, Carlos Engler-Pinto
An innovative specimen design and test system for thermal fatigue (TF) analysis is developed to compare the fatigue behavior of different cylinder head materials under realistic cyclic thermal loadings. Finite element analyses were performed to optimize the specimen geometry and thermal cycles. The reduced section of the TF specimen is heated locally by a high frequency induction heater and cooled by compressed air. The mechanical strain is then induced internally by the non-uniform thermal gradient generated within the specimen to closely simulate what valve bridges in cylinder heads experience in real operation. The resulting fatigue life is a function not only of the inherent fatigue resistance of the alloys, but also of other relevant properties such as thermal conductivity, modulus of elasticity, and coefficient of thermal expansion. This test is an essential tool for comparing different alloys for thermal fatigue applications.
2018-04-03
Technical Paper
2018-01-1415
Leslie Bromberg, Daniel cohn
Direct Injection (DI) fueled gasoline engines provide higher efficiency than port fueled injected (PFI) engines. However, emission of small particulates is greatly increased when DI is used. Particulate mass emission is increased by more than a factor of 10 and particulate number is increased by a factor of 10-100 relative to PFI engines leading to health concerns and to implementation and consideration of new regulations. Optimized combinations of PFI and DI can greatly reduce DI-generated particulate emissions without compromising efficiency and performance. A DI enhanced PFI mode of engine operation is employed where PFI is the dominant means in dual injection fueling over a drive cycle, and the fuel fraction that is directly injected is reduced/minimized while still preventing knock at high loads. Further reduction can be obtained by optimal use of spark retard.
2018-04-03
Technical Paper
2018-01-1416
Justin E. Ketterer, Erwan Gautier, Edward J. Keating
In conventional spark-ignition engines, the expansion ratio – a key determinant of efficiency – is equal to the geometric compression ratio. Part-load efficiency may be improved by increasing the compression ratio, but this is limited by knock at high loads. To achieve a high expansion ratio while limiting the effective compression ratio to avoid knock, intake timing and duration may be manipulated to limit trapped charge. Miller Cycle engines employ this strategy coupled with forced induction. The Miller effect may be achieved using either early or late intake valve closure. Combustion systems for these engines must be carefully designed to obtain adequate trapped charge as well as charge motion characteristics supporting good mixture preparation and flame propagation. This paper summarizes the results of a project tasked with developing robust combustion systems for both early and late intake valve closure strategies.
2018-04-03
Technical Paper
2018-01-1413
Jaime Martin, Francisco Arnau, Pedro Piqueras, Angel Auñon
The combination of more strict regulation for pollutant and CO2 emissions and the new testing cycles, covering a wider range of transient conditions, makes very interesting the development of predictive tools for engine design and pre-calibration. This paper describes a new integrated Virtual Engine Model (VEMOD), which has been developed as a standalone tool to simulate new standard testing cycles. The VEMOD is based on a wave-action model that carries out the thermo-and fluid dynamics calculation of the gas in each part of the engine. In the model, the engine is represented by means of 1D ducts, while the volumes, such as cylinders and reservoirs, are considered as 0D elements. Different sub-models are included in the VEMOD to take into account all the relevant phenomena. Thus, the combustion process is calculated by the Apparent Combustion Time (ACT) 1D model, responsible for the prediction of the rate of heat release, CO2 and NOx emissions.
2018-04-03
Technical Paper
2018-01-1420
Sandip Wadekar, Michael Oevermann, Andrei Lipatnikov
Stratified combustion in gasoline engines constitutes a promising means of achieving higher thermal efficiency for low to medium engine loads than that achieved with combustion under standard homogeneous conditions. However, creating a charge that leads to a stable efficient low-emission stratified combustion process remains challenging. Combustion through a stratified charge depends strongly on the dynamics of the turbulent fuel-air mixing process and the flame propagation. Predictive simulation tools are required to elucidate this complex mixing and combustion process under stratified conditions. For the simulation of mixing processes, combustion models based on large-eddy turbulence modeling have typically outperformed the standard Reynolds averaged Navier-Stokes methods.
2018-04-03
Technical Paper
2018-01-1418
Dongchan Kim, Yilong Zhang, Lewis Clark, Sanghoon Kook, Yi Gao
Stringent particulate emission regulations have been recently applied to spark-ignition direct-injection (SIDI) engine, calling for significant in-cylinder reduction of soot particles. These mandatory standards will be tall orders without understanding the soot formation and oxidation process within the flame. To bridge this gap, the present study a new thermophoresis-based sampling system has been developed and implemented in a working SIDI engine. Using the multiple probes installed on the piston top, the soot particles are directly sampled from the petrol flame for a close investigation on soot morphology. At the probe tip, a transmission electron microscope (TEM) grid is stored for the soot collection, which is imaged and post-processed for statistical analysis of particle size distribution and fractal dimension.
2018-04-03
Technical Paper
2018-01-1423
Graham Conway, Dennis Robertson, Chris Chadwell, Joseph McDonald, John Kargul, Daniel Barba, Mark Stuhldreher
Low-pressure loop (LPL) EGR combined with higher compression ratio is a technology package that has been the focus of significant research to increase engine thermal efficiency on downsized, turbocharge GDI engines. Research shows that the addition of LPL-EGR reduces the propensity to knock that is experienced at higher compression ratios [1]. To investigate the interaction and compatibility between increased compression ratio and LPL-EGR, a 1.6 L Turbocharged GDI engine was modified to run with LPL-EGR at a higher compression ratio (12:1 versus 10.5:1) via a piston change. The paper presents the results of the baseline testing on a PSA engine run with a prototype SwRI controller and initially tuned to mimic OEM baseline control strategy running on premium fuel (92.8 AKI). The paper then presents test results after first adding LPL-EGR to the baseline engine, and then also increasing CR (using 12:1 pistons).
2018-04-03
Technical Paper
2018-01-1424
Yogesh Vasantrao Magar, Sundar D
Abstract: Gasoline engines with Multi point fuel injection (MPFI) technology are being developed with naturally aspirated and/or turbocharged engines. Wherein a combination MPFI and turbo charged engines have certain challenges during development stages. One of the important challenge is balancing between drivability and emission. With MPFI turbocharged engine combination, the under bonnet heat management is crucial task for drivability. The heat management of air intake plays a vital role in drivability part therefore a design layout of air intake path is an important aspect. Drivability can be categorized as low end, mid range and top end drivability. Turbocharged MPFI engines have a typical phenomenon of ‘Lag in response’ in the low-end region. This ‘Lag in response’ phenomenon at low-end drivability region can be overcome through optimization air intake system, optimization of exhaust back pressure and through EMS calibration tuning.
2018-04-03
Technical Paper
2018-01-1421
Adrian Irimescu, Simona Merola, Santiago Martinez
Alternative combustion control in the form of lean operation offers significant advantages such as high efficiency and ‘clean’ fuel oxidation. Maximum dilution rates are limited by increasing instability that can ultimately lead to partial burning or even misfires. A compromise needs to be reached between high tumble-turbulence levels that ‘speed-up’ combustion, and the inherent stochastic nature of this fluid motion. The present study is focused on gaining improved insight into combustion characteristics through thermodynamic analysis and flame imaging, in a wall guided direct injection spark ignition engine with optical accessibility. Engine speed values were investigated in the range of 1000 to 2000 rpm, with commercial gasoline fueling, in wide open throttle conditions; mixture strength ranged from stoichiometric, down to the equivalence ratios that allowed acceptable cycle-by-cycle variations.
2018-04-03
Technical Paper
2018-01-1422
Qinhao Fan, Zhi Wang, Yunliang Qi, Yingdi Wang, Yanfei Li, Yitao Shen
In order to meet increasingly stringent fuel consumption and emission regulations, more attentions are paid to engine efficiency. A large quantity of energy-saving technologies have been applied in automotive field especially in gasoline engines, such as turbo-downsizing-direct injection, cooled EGR, long stroke, high tumble and so on. However, the efficiency of gasoline engine is still lower than advanced DI diesel engine. Thus, further improvement in thermal efficiency is essential. It is known that lean burn and ultra-high compression are two root methods to increase efficiency. In this paper, a rapid compression machine is employed to study the combustion process of lean iso-octane mixture at ultra-high compression ratios. The ignition of the mixture is triggered by a spark plug at the timing right after the end of compression, then the flame propagation and end-gas auto-ignition is recorded using high-speed photography.
2018-04-03
Technical Paper
2018-01-1426
Martin Großbichler, Zhen ZHANG, Harald Waschl
To meet current legislation limits, modern diesel engines already achieve very low raw emission levels and utilize additional components for aftertreatment. However, during fast transients still undesired emission peaks can occur for both soot and NOx. These are caused by differences in the in-cylinder conditions between the quasi steady state engine calibration and the transient engine operation, e.g. during tip-ins. These effects become more and more important in view of future RDE emission test cycles. In this work a case study is performed to analyze the potential reduction of transient soot emissions during a specified engine maneuver. An additional target is to investigate potential benefits of a novel in-situ soot sensor based on the Laser Induced Incandescence (LII) principle which offers a high temporal resolution.
2018-04-03
Technical Paper
2018-01-1425
Jiri Navratil
The upcoming World-harmonized Light-duty Vehicles Test Cycle (WLTC) together with the Real Driving Emissions (RDE) legislation used for the assessment of fuel economy and emissions, demand a start from a cold engine state. The process of warming up the engine from a cold start has a significant contribution to the emissions and fuel economy of the entire drive cycle. The process involves a multitude of interdependent components which means that modelling the phenomena has so far only been achieved using highly simplified approaches or accepting a very large penalty on calculation time. This paper presents modelling of the real-time running virtual vehicle whose parts are built in different domains connected with the Functional Mock-up Interface (FMI) co-simulation standard. A real-time 1-D gas thermodynamics code ‘WAVE-RT’ is used as a virtual gasoline engine providing detailed information about any chosen parameters at every engine crank angle.
2018-04-03
Technical Paper
2018-01-1428
David Culbertson, Magdi Khair, Yuhui Zha, Jeff Diestelmeier
Real world driving conditions and tightening legislations require improved performance of aftertreatment systems at lower temperatures. Electric heat has been shown to be a feasible means of heating exhaust, but having a practical means to provide power and control for the heater has been a barrier for implementation. Recent testing has demonstrated the ability of a 24Vdc heating & control system to effectively heat exhaust using only conventional alternator and battery power sources. Results from transient cycles show the effectiveness of the electrical system and the extent of exhaust heating.
2018-04-03
Technical Paper
2018-01-1427
haijiang LIU, Wei Huang
Reasonable calibration can improve vehicle drivability of the mode of engine starts. Aiming at the problem that calibration standard is not perfect, which rising a difficult issue to how to calibrate engine management system reasonably. In this paper, drivability influencing factors of vehicle was analyzed from the control for engine management system under the mode of engine start and engine stop. Furthermore, the evaluation model of drivability of engine starts was established which provided a repeatable and quantifiable method for the calibration of engine management system. The drivability influencing indexes was analyzed from the subjective feeling of drivers and dynamic change on engine starts process, and according to the process of engine start, crank time, start time, return to idle time, overshoot, undershoot and surge were considered.
2018-04-03
Technical Paper
2018-01-1430
Changho Jung, Pyung Soon Kim, Mi-Young Kim, Eunseok Kim, Chang Kim
Improved Lean NOx Trap (LNT) catalysts with enhanced NH3 generation feature were developed for the small diesel engine. The next generation LNT system needs to perform high NOx conversion over wide temperature range including high temperature and high flow rate of real road driving. However, the extended use of BaO, a component of LNT known to be very effective for high temperature NOx absorption, causes the decrease of low temperature NOx conversion due to the degradation of oxidation performance and desulfation efficiency over time. The improvement of the low temperature LNT performance is a key requirement for the real driving emission control as the operation temperature for the best performance of urea-SCR is above ~250 C. In this study, our next generation LNT with new washcoat architecture has demonstrated improved high temperature NOx removal efficiencies under the wider operation temperature window than the current production technology.
2018-04-03
Technical Paper
2018-01-1429
Mufaddel Dahodwala, Satyum Joshi, Erik W. Koehler, Michael Franke, Dean Tomazic
When considered along with Phase 2 GHG requirements, the proposed ARB NOx emission limit of 0.02 g/bhp-hr will be very challenging to achieve as the trade-off between fuel consumption and NOx emissions is not favorable. To meet any future ultra-low NOx emission regulation the NOx conversion efficiency during cold start emission test cycles needs to be improved. In such a scenario, apart from changes in aftertreatment layout and formulation, additional heating measures will be required. In this paper, a physics-based model for an advanced aftertreatment system comprising of a DOC, an SDPF, a standalone SCR and an ammonia slip catalyst were calibrated against experimental data. The calibrated model was then used to evaluate different advanced aftertreatment systems comprising of an electrically heated catalyst, mini-burner, fuel dosing, passive NOx adsorber and ammonia injection.
2018-04-03
Technical Paper
2018-01-1432
Senthil Ramalingam, Silambarasan Rajendran
The limited work has been done so far using neat biodiesel in the diesel engine since it drastically reduces the brake thermal efficiency and emitting higher amount of oxides of nitrogen. Hence in the present investigation an attempt has been made to use neat biodiesels in DI diesel engine on par with diesel fuel with some alternate methods that have to be incorporated to improve the efficiency and to reduce the NOx emission.The biodiesels used for the present investigation are nerium, mahua and calophyllum and these biodiesels are easily available and very cheaper when compared to that of other biodiesels. The catalyst coated combustion is created by using catalyst ZrO2and used to improve the performance of the engine. Further, the anti-oxidant fuel additive such as L-ascorbic acid can contribute towards fuel economy and emissions reduction either directly or indirectly in the diesel engines.
2018-04-03
Technical Paper
2018-01-1431
Thirumal Valavan Harikrishnan, Abinav Sunder, John Hoard
Cold start emissions constitute around 60% to 80% of all the hydrocarbon & CO emissions in present day vehicles. The time taken to achieve the catalyst light-off temperature in a three-way catalytic converter significantly affects the emissions and fuel efficiency. The current work aims at development of a method to retain heat in catalytic converter, thus avoiding the need for light-off and reducing cold start emissions effectively. Various techniques under study involve recovering heat from exhaust gases downstream of catalyst bricks, composite insulation with different materials and geometry optimization of the phase change material around the catalyst bricks to increase the heat absorption rate and storage capacity for prolonged cool down periods. Analytical models were developed and the variants were tested using real-world cycle data. Two variants were studied in particular with modifications made to the thickness of the insulation layer and PCM layer.
2018-04-03
Technical Paper
2018-01-1434
Prashant Kumar, Ashish Kumar Kachhawa, Sanjeev Kumar
The increasing number of vehicles on the road, particularly in the big cities, has considerable negative effects on the environment in terms of toxic emissions. Although, there have been significant improvement with the development of catalytic converters, electronic injection equipment and other advanced systems for on-road vehicles; however, the burden on environment caused by road transport is still high and constantly increasing. Under these circumstances, substitution of conventional fuels by the "clean fuel" natural gas could help reduce emissions and lead to an effective improvement of air quality, particularly in urban areas. Natural gas can be used in normal four-stroke spark ignition engines without any technical problems. Diesel engines, however, require to be converted to CNG combustion. Indian Oil Corporation limited has been always in the forefront for utilization of cost effective alternative energy options endowed with benefits to environment.
2018-04-03
Technical Paper
2018-01-1433
Sunil Pathak
The rapidly increasing number of vehicles on the roads have posed the problem of excessive emissions which is one of the major contributors towards air pollution is not limited to metropolitan cities and increasing rapidly in smaller cities of India. The policy makers have been trying hard to control air pollution by implementing fuel quality and stringent emission norms, promoting electrical vehicles and new policy measures, such as ODD-EVEN schemes to limit the use of privately owned vehicles. The present work analyses driving cycles and driving characteristics of the vehicles heavy duty CNG buses to study the change in the vehicular emissions and its contribution towards the pollution in the city’s air during the famous odd-even policy was applied twice in Delhi for two weeks in winter and Summer season. The speeds and positions of the buses were collected by speed sensors and GPS data logging and a database of speed distributions was prepared.
2018-04-03
Technical Paper
2018-01-1436
Michael Papageorge, Jeff Colwell
Hot surface ignition of combustible material is a known cause of vehicle fires. Although the detailed mechanisms of hot surface ignition are highly complex, the surface temperature is known to play a crucial role in this process. There has been limited previous work in the literature on this topic, much of which has focused on engine or exhaust system surface temperatures of the most common types of passenger vehicles. Also, much of this work was done in an unrepeatable manner and suffered from measurement technique induced errors. The focus of the present work is on repeatable and low error temperature measurements of exhaust system surface temperatures of high-performance rear- and mid-engine sports cars. Temperature measurements were made at several points along the exhaust systems of vehicles both with and without turbo chargers on a 5-mile oval track.
2018-04-03
Technical Paper
2018-01-1438
Juner Zhu, Xiaowei Zhang, Tomasz Wierzbicki, Yong Xia, Guanhua Chen
Ground impact caused by road debris can result in very severe fire accident of Electric Vehicles (EV). In order to study the ground impact accidents, a Finite Element model of the battery pack structure is carefully set up according to the practical designs of EVs. Based on this model, the sequence of the deformation process is studied, and the contribution of each component is clarified. Subsequently, four designs, including three enhanced shield plates and one enhanced housing box, are investigated. Results show that the BRAS (Blast Resistant Adaptive Sandwich) shield plate is the most effective structure to decrease the deformation of the battery cells. Compared with the baseline case, which adopts a 6.35-mm-thick aluminum sheet as the shield plate, the BRAS can reduce the shortening of cells by more than 50%. Another type of sandwich structure, the NavTruss, can also improve the safety of battery pack, but not as effectively as the BRAS.
2018-04-03
Technical Paper
2018-01-1437
Jeff Colwell, Benjamin Knox
Two full-scale burn tests involving identical side-by-side all-terrain vehicles were conducted to evaluate fire spread, changes in temperature distributions over time, and how burn patterns created correlated to the known point of origin of the fires. The fires were initiated by igniting body panels at opposite corners of the vehicles such that in one test the fire propagated down wind and, in the other, it propagated upwind. In both tests, drop-down from the body panels onto the tires, which then resulted in ignition of the tires, was an important feature of the mechanism of fire spread. Once the tire began to burn, the rate of fire spread increased followed by rapid spread throughout the remainder of the vehicle until it self-extinguished. The variation of damage to painted surfaces, oxidation patterns on steel surfaces, and melt damage to aluminum components after the fire were similar in both vehicles but were not useful in determining the area of origin of the fire.
2018-04-03
Technical Paper
2018-01-1441
Peter Xing, Mike Yang, Brandon Tsuge, Thomas Flynn, Jonathan Lawrence, Gunter P. Siegmund
Many Toyota vehicles incorporate a Vehicle Control History (VCH) Event Data Recorder (EDR). Unlike common airbag EDRs, the VCH EDR records non-collision events like the activation of the vehicle’s Autonomous Emergency Braking (AEB) system. The VCH records up to 5 seconds of pre-trigger and 5 seconds of post-trigger data including vehicle speed, distance to hazard and activation timing of various AEB warning and braking systems. The accuracy of this data has not been studied previously. A 2017 Toyota Corolla with Safety Sense P was equipped with an external fifth-wheel and a data acquisition (DAQ) system which recorded the AEB warning buzzer and brake light. The car was driven in a straight line towards a car-like target at 30 to 40 km/h until the AEB system activated. A comparison between the VCH data and the fifth wheel and DAQ data revealed that the VCH under-reported the vehicle speed and over reported the distance to target.
2018-04-03
Technical Paper
2018-01-1443
Edward Fatzinger, Jon Landerville
Electronic control units (ECU) from Kawasaki Ninja ZX-6R and ZX-10R motorcycles were tested in order to examine the capabilities and behavior of the event data recorders (EDR). The relevant hexadecimal data was downloaded from the ECU and translated using known and historically proven applications. The hexadecimal translations were then confirmed using data acquisition systems as well as the Kawasaki Diagnostic Software (KDS). Numerous tests were performed to establish the algorithms which cause the EDR to record data. Issues of sensor and power loss were analyzed and discussed. Additionally, data sets were studied that involved maximum deceleration from ABS brakes. Similarly, data sets that involved traction control intervention were studied and analyzed. It was determined that the EDR recording ‘trigger’ was caused by the activation of the tip-over sensor, which in turn shuts the engine off.
2018-04-03
Technical Paper
2018-01-1444
Krishnakanth Aekbote, Clifford Chou, James Cheng, King Yang, John Cavanaugh, Stephen Rouhana, Jamel Belwafa
An understanding of stiffness characteristics of different body regions, such as thorax, abdomen and pelvis of ES-2re and SID-IIs dummies under controlled laboratory test conditions is essential for development of both compatible performance targets for countermeasures and occupant protection strategies to meet the recently updated FMVSS214, LINCAP and IIHS Dynamic Side Impact Test requirements. The primary purpose of this study is to determine the transfer functions between the ES-2re and SID-IIs dummies for different body regions under identical test conditions using flat rigid wall sled tests. The experimental set-up consists of a flat rigid wall with five instrumented load wall plates aligned with dummy's shoulder, thorax, abdomen, pelvis and femur/knee impacting a stationary dummy seated on a rigid low friction seat at a pre-determined velocity.
2018-04-03
Technical Paper
2018-01-1447
Sanketh Gowda, Anindya Deb, Goutham Kurnool, Clifford C. Chou
Recent experimental studies on the behavior of adhesively-bonded steel double-hat section components under axial impact loading have produced encouraging results in terms of load-displacement response and energy absorption when compared to traditional spot-welded hat sections. However, it is extremely difficult to come across any published work on the behavior of such components under transverse impact loading keeping in mind applications such as automotive body structures subject to lateral/side impact. In the present work, experimental lateral impact studies have been carried out on adhesively-bonded double-hat section components and the performance of such components has been compared against their conventional spot-welded and hybrid counterparts. It is clarified that hybrid components in the present context refer to adhesively-bonded hat sections with a few spot welds only aimed at preventing catastrophic flange separations.
Viewing 181 to 210 of 86934