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Technical Paper
2014-11-11
Tatsuhiko Sato, Hirotaka Kurita, Akemi Ito, Hideyuki Iwasaki
The frictional force generated between an actual monolithic aluminum cylinder block and a piston / a piston-ring in a firing mode was measured with using a newly developed floating liner device for the first case in the world. The improvement of fuel consumption is the most important issue for engine manufactures from the viewpoint of energy and environment conservation. The piston-cylinder system plays quite important role for the reduction of the engine friction. For the improvement of the frictional behavior of the piston-cylinder system, it is beneficial to observe and analyze the frictional waveforms during an engine operation. In order to meet the above-mentioned demand, the renewed floating liner device was developed. In the newly developed floating liner device, the actual cylinder block itself was used as a test specimen, whereas a thin-walled cylindrical sleeve should be used as the test specimen in the conventional floating liner device. The measured single cylinder was an aluminum monolithic type made of hypereutectic Al-17Si alloy using a high pressure die casting process.
Technical Paper
2014-11-11
Sara Gronchi, Raffaele Squarcini
In recent years, the automotive industry, in case of both small and large size engine, is experiencing different technological and scientific levels of investigation thanks to the new market requests. For example, many different aspects should be evaluated in volumetric oil pumps: flow rate, back flow, filling chamber, pressure ripples and so on. All these features are fundamental fluid dynamic outputs, each aimed at defining a different aspect of the pump. For this reason, each of them requires different levels of precision. Focusing on the hydraulic pressure ripples calculation, several levels of accuracy are required in order to define the pressure profile according to the type of analysis for which you want to use it. By noise emission, as in this case, where the hydraulic load is the main input , the calculation should necessarily be a high performance fluid dynamic simulation. In this way it is possible to validate the pressure signal calculated with the presence of high frequencies and higher pump orders as in the experimental one so that the input for the numerical and experimental methodology can be compared.
Technical Paper
2014-11-11
Giovanni Vichi, Luca Romani, Giovanni Ferrara, Luca Carmignani, Francesco Maiani
In the last years, the engineering in the automotive industry has been revolutionized by the continuous research in the reduction of consumption and pollutant emissions. On this topic there is the maximum attention both by the legislative bodies and by the costumers. The more and more severe limitations in pollutant and CO2 emissions imposed by international standards on the engine manufacturers and the increasing price of the fuel force the automotive research to more efficient and ecological engines. The standard approach for the definition of the engine parameters at the beginning of the design process is based on wide open throttle condition although, both in homologation cycles and in the real utilization, engines work mainly in partial load where the efficiency dramatically decreases. This aspect has recently become strongly relevant also for two-wheels vehicles especially for urban purpose. Within this context the authors developed an integrated numerical model, in MatLab Simulink ambient, in order to couple the engine simulation, performed by means of a 1D computer-aided engineering code, with the whole vehicle dynamic behaviour.
Technical Paper
2014-11-11
Francesco Maiani, Alessio Sisi, Walther Leardini
In recent years the 2-wheelers engines companies are focused on increasing the overall engine efficiency, that can be gained through engine down-speeding, engine down-sizing and by reducing the frictions; however, to maintain or improve vehicle performance, it is necessary to provide a corresponding increase in specific power. In accordance with these trends, the studied approaches and methodologies have been exploited, during the development of the new Piaggio small scooter engine. In this work a multi-target analysis has been applied to the valvetrain system design, in order to optimize engine performance in terms of friction reduction, power curve and dynamic response of the timing system. Along with this optimization methodology, a robust design has been studied and applied to make the peak cranking compression pressure insensitive to engine starting device working. These calculation methodologies was achieved using commercial software as GT–SUITE for engine performance and valvetrain simulation and modeFRONTIER for multiobjective optimization analysis.
Technical Paper
2014-11-11
Jonathan Tenenbaum, Michael Shapiro, Leonid Tartakovsky
Two-phase jets are found in a variety of applications, including ink-jet printers, spray cooling, etc. Fuel sprays in internal combustion engines is an application of particular interest because of its direct influence on engine performance, energy efficiency and pollutants formation. Many phenomenological models have been proposed to quantify the temporal behavior of spray properties such as spray penetration with time, spray dispersion angle and cross-sectional averaged fuel concentration. However, most of the existing models have the limitation of providing a one-dimensional description and are thus unable to adequately describe the spatial point-wise spray distribution, in particular the local fuel concentration and mixture velocity. The aim of this study is to develop a more elaborate spray model which allows for calculation of spatial local fuel concentration and mixture velocity. The model is based on the single-phase steady-state laminar axisymmetric jet flow field solution by Schlichting, which is applied for a two-phase jet in the limit of dilute fuel concentration.
Technical Paper
2014-11-11
Rama Subbu, Baskar Anthony samy, Piyush mani Sharma, Prasanna Mahendiran
Ride comfort, driving stability and drivability are vital factors in terms of vehicle performance and the customer satisfaction. Crankshaft balancing is the source for the vibration that reduces the vehicle performance and it need to be controlled to some extent such that the vehicle performance will be improved. The IC engine is made up of reciprocating and rotating parts and they produce unbalanced forces during their operation and produce the vibratory output at the vehicle supporting members. The vibration reduction will be possible by minimizing unbalanced forces and by optimizing the crankshaft at the two wheeled vehicle engine design. Many researches were made to find the causes for the vibration and to reduce the vibrations at the engine supports. But still there is a research gap on the testing and simulation of engine components (crankshaft, connecting rod and piston assembly) and the correlation between the testing and simulation. In this work, an attempt is made to represent the engine vibrations and its isolations and to provide a gate way for the future work on it.
Technical Paper
2014-11-11
Akira Ishibashi, Muneaki Nakamura, Hitoshi Muramatsu, Seizaburo Katsuta
Fuel economy improvement has become the most important issue in automobile engine developments nowadays. For the purpose of improving fuel economy due to the higher thermal efficiency, the enhancement of compression ratio and the reduction of thermal loss through cooling have been conducted widely. Those efforts exerted in the ongoing developments to improve thermal efficiency increase the thermal load on pistons. Considering the reliability of the pistons and anti-knocking capacity of engines, it is necessary to make a better understanding of piston temperature distributions through accurate measurement under various engine operating conditions. Thus, direct and indirect measurement methods have been developed to estimate the actual piston temperature. The direct method, such as linkage-type is not typically available under higher engine speed due to the durability of linkages. The indirect method, such as material hardness-type can neither measure real-time piston temperature nor measure temperature of piston skirts which are thin-walled.    
Technical Paper
2014-11-11
Tomokazu Nomura, Koichiro Matsushita, Yoshihiko Fujii, Hirofumi Fujiwara
To meet growing demands on the fuel economy, various studies have been made to improve thermal efficiency of engines. In spite of such efforts, approximately 30% of fuel energy is still dissipated to the atmosphere finally as cooling loss, through engine parts, coolant and oil. Therefore, if the heat dissipation from the engine is insufficient, the temperature of engine parts rises. An excessively higher engine temperature causes a degradation of engine performance and a deterioration of material strength. Especially in air-cooled engines, there are contradicting demands between the heat dissipation capacity and the light weighted compactness. Therefore, to realize the optimized design for a light and compact engine, a method of a precise temperature prediction is required in the early stage of the development. A number of studies have been made on the cooling performance and the temperature prediction of engines. In many of such studies, temperature of an engine cannot be directly estimated but heat transfer from the engine to the atmosphere and to the coolant are evaluated on the basis of heat transfer coefficients calculated by 3D-CFD.
Technical Paper
2014-11-11
Mohamed El morsy, Gabriela Achtenova
Through PULSE platform for vibration analysis, which is developed as an advanced solution for vibration measurements was developed the robust diagnostic concept (RDC). The PULSE setup is designed to help in fault diagnosis of vehicle gearbox -the main part of vehicle powertrain-. Time Domain, Continuous Wavelet Transformation Technique (CWT), FFT and Order analysis measurements are used for detection of an artificial pitting defect in gear by tracking the gearbox response at accelerated speed and different load. The test stand is equipped with three dynamometers; the input dynamometer serves as internal combustion engine, the output dynamometers introduce the load on the flanges of output joint shafts. The pitting defect is manufactured on the tooth side of gear of the fifth speed on the intermediate shaft. Temperature effect on the vibration measurements has been also investigated to study its effect on the fault diagnosis. The presented concept has an important application in the field of mechanical fault diagnosis.
Technical Paper
2014-11-11
Toshio Watanabe, Hiroki SAKAMOTO
It is well known that for high-speed planing craft with outboard motor, cavitation occurs around the lower unit(gear case) and propeller blades. There are several kinds of cavitation; (1)Tip vortex cavitation (2)Hub vortex cavitation (3)Sheet cavitation (4)Cloud cavitation (5)Root cavitation Among them ,Cloud cavitation and root cavitation lead to erosion damage on the surface of lower unit and propeller. To prevent from poor appearance or performance deterioration of outboard motor by erosion damage, It is important to simulate the occurrence of erosion in advance at the design stage. In this paper, we propose the new method of predicting the area that erosion occurs using CFD (computational fluid dynamics). In order to simulate cavitation phenomena, basically, we have implemented the CFD analysis using the barotropic model. But the area that cavitation occurs does not correspond to the position of erosion damage. Therefore, we focus on the bubble nucleus which is due to cavitation. First, we predict cavitation phenomena on the basis of single-bubble motion with Rayleigh plesset model.
Technical Paper
2014-11-11
Yoshihiro Nakagawa, Shinya Takahashi, Mikihito Masaki, Ranju Imao
In brake squeal analysis using FE models, minimizing differences in natural frequency between the measurement and the simulation in each component are a key issue for improvement in reproducibility of brake squeal. In the evaluations of model-measurement correlations in the study of brake discs, if amounts of shifts in natural frequencies and their deviation orientations, between the measured and simulated, have the same tendency in each vibration mode, the gaps between the measurements and simulations are relatively easy to be corrected to match to each other by adjusting parameters of densities and/or Young’s moduli. However, these tendencies in natural frequency differences vary depending on the situations and the opposite tendencies may appear in some cases. In such cases, the model-measurement gaps in natural frequency cannot be adequately reduced by adjusting densities and/or Young’s moduli. The potential cause of this model-measurement gap was assumed to be the residual stresses, which were imposed during the inductive hardening process of the brake disc to increase the hardness of the sliding surfaces.
Technical Paper
2014-10-13
Yongqiang Han, Jianjian Kang, Xianfeng Wang, Yang Chen, Zhichao Hu
Energy saving and environment protection has been two major subjects in the development of automobile industry. In the internal combustion engine, about 40% of fuel energy is released into the atmosphere through waste gas. The recovery and utilization of the heat from waste gas can realize the goals of energy saving and cost reducing. In fieldof waste heat recovery, the organic Rankine cycle (ORC) has good prospects and has been widely used.Turbo has been selected firstly as the expander in traditional ORC. However, turbo has disadvantages of high manufacturing cost and narrow applicable range. In this paper, a new organic Rankinecycle coupling free piston (ORC-FP) system used in theinternal combustion engine (ICE) exhaust heatrecovery is proposed and its working principle is introduced in detail.In this system, the free piston with constant force outputfunctions as expander in ORC and operates reciprocally to output workunder the driven of working fluid R245ca,which absorbs heat from waste gas and provides vapor power.
Technical Paper
2014-10-13
Di Zhu, Ewan Pritchard
EcoCAR 2: Plugging in to the Future is a three-year collegiate engineering competition established by the U.S. Department of Energy (DOE) and General Motors (GM). North Carolina State University is designing a Series Plug-in Hybrid Electric Vehicle (PHEV) on a 2013 Chevrolet Malibu vehicle platform. The designed vehicle has a pure electric range of 55 miles and an overall range of 235 miles with a range extension system. The vehicle is designed to reduce fuel consumption and gas emission while maintaining consumer acceptability in the areas of performance, utility, and safety. This reports details the vehicle development process with an emphasis on control system development and refinement. Advanced manufacturing, modeling, and simulation have been used to ensure a safe and functional vehicle at the upcoming year 3 final competition.
Technical Paper
2014-10-13
R. Pradeepak, Mihir Bhambri
Motor scooters are popular in most parts of the world, especially in countries with local manufacturers. Parking, storage, and traffic issues in crowded cities, along with the easy driving position makes them a popular mode of transportation. Motor scooters are the segment of 2 wheelers which is driven by the entire family with ease unlike motorcycles which is a male dominated segment. Due to the importance that the scooters hold in the present time, it has become very important to manufacture stable, light weight yet robust scooters. For the best product in the market, testing is given a great importance in automotive manufacturing companies. Virtual testing has been the latest development in terms of testing a vehicle during the design stage itself. Multi Body Dynamics approach is used to study - 1) the articulation of various sub-assemblies and 2) the static & dynamic loads generated at various attachment points of the scooter. Integration of sub-assemblies into a final product creates a minimal scope of modification of the location of different components.
Technical Paper
2014-10-13
Jacek Andrzej Czarnigowski
The search for environmentally friendly fuels and ways of reducing carbon dioxide emissions is the main cause of a growing interest in gaseous fuels and corresponding fuel systems for internal combustion engines. To assure the expected environmental advantages with no detriment to the engine performance, these fuel systems need to be equipped with precise actuators – the gas injectors. The key input required in the process of designing and calibrating such fuel systems are precise characteristics of the injectors and understanding what affects these characteristics. The paper presents the results of experiments on the effects of supply pressure and supply voltage on the pulse gas injector opening time. Two characteristics have been investigated into: the opening lag time and the opening time. The opening lag was defined as the time between the occurence of a control signal and the moment of the valve’s starting to move. The lag determines the minimal duration of the control signal that can be executed by the injector, and thus the injector’s applicability.
Technical Paper
2014-10-13
Bo Hu, Chris Brace, Sam Akehurst, Colin Copeland, J.W.G. Turner
One of the major limits for two-stage-regulated turbocharged SI engines is its large backpressure and the corresponding degraded combustion efficiency. Divided exhaust period (DEP) concept is an approach which has been proved to significantly reduce the backpressure while still maintaining the same engine performance. The standard layout of the DEP system only comprises of a single turbocharger. Two exhaust valves are separately functioned with one valve feeding the blow-down pulse to the turbine whilst the other valve targeting the scavenging by bypassing the turbine. This method can provide large BSFC improvement due to improved breathing characteristics and better combustion phasing. The DEP concept has only been applied to single turbocharged engines so far. However, it in its basic form is in no way restricted to one-stage system. This paper, for the first time, applied DEP concept to a two-stage-regulated downsized SI engine. By controlling the timing of the exhaust valves separately to feed the exhaust to the high-pressure-turbine or low-pressure turbine or the exhaust pipe, it is anticipated that such system could achieve even better breathing characteristics than the standard one-stage turbocharged engine.
Technical Paper
2014-10-13
Chris D. Monaco, Chris Golecki, Benjamin Sattler, Daniel C. Haworth, Jeffrey S. Mayer, Gary Neal
As one of the fifteen universities in North America taking part in the EcoCAR 2: Plugging into the Future competition, The Pennsylvania State University Advanced Vehicle Team (PSUAVT) designed and implemented a series plug-in hybrid electric vehicle (PHEV) that reduces fuel consumption and emissions while maintaining high consumer acceptability and safety standards. This architecture allows the vehicle to operate as a pure electric vehicle until the Energy Storage System (ESS) State of Charge (SOC) is depleted. The Auxiliary Power Unit (APU) then supplements the battery to extend range beyond that of a purely electric vehicle. General Motors (GM) donated a 2013 Chevrolet Malibu for PSUAVT to use as the platform to implement the PSUAVT-selected series PHEV design. A 90 kW electric traction motor, a 16.2 kW-hr high capacity lithium-ion battery pack, and Auxiliary Power Unit (APU) are now integrated into the vehicle. The APU is a 750cc, two-cylinder engine running on an 85% ethanol/15% gasoline (E85) mixture coupled to an electric generator.
Technical Paper
2014-10-13
Arash Hamzehloo, Pavlos Aleiferis
International obligations to reduce carbon dioxide emissions and requirements to strengthen security of fuel supply, indicate a need to diversify towards the use of cleaner and more sustainable fuels. Hydrogen has been recommended as an encouraging gaseous fuel for future road transportation since with reasonable modifications it can be burned in conventional internal combustion engines without producing carbon-based tailpipe emissions. Direct injection of hydrogen into the combustion chamber can be more preferable than port fuel injection since it offers advantages of higher volumetric efficiency and can eliminate abnormal combustion phenomena such as backfiring. The current work applied a fully implicit coupled computational methodology along with Reynolds-Averaged Navier-Stokes (RANS) technique in order to study the mixture formation and combustion in a direct-injection spark-ignition engine with hydrogen fuelling. Hydrogen was issues into the combustion chamber by a six-hole side-mounted injector.
Technical Paper
2014-10-13
Mohd Farid Muhamad Said, Azhar Bin Abdul Aziz, Zulkanain Abdul Latiff, Amin Mahmoudzadeh Andwari, Shahril Nizam Mohamed Soid
Many efforts have been invested to improve the fuel efficiency of vehicles mainly for the local consumers. The production of a downsized turbocharged engine in the last quarter of 2011 proves that Malaysian is racing towards producing high efficiency engines along with other manufacturers. The effort does not only end there, several research activities on other alternative technology including cylinder deactivation (CDA) has begun. In this paper, the main research area is focus on the investigation of cylinder deactivation (CDA) technology on common engine part load conditions within Malaysian city driving operation. CDA mostly being applied on multi cylinders engines. It has the advantage in improving fuel consumption by reducing pumping losses at part load engine conditions. Here, the application of CDA on 1.6 liter four cylinders gasoline engine is studied. One-dimensional (1-D) engine modeling is performed to investigate the effect of intake and exhaust valve strategy on engine performance with CDA.
Technical Paper
2014-10-13
Lyes Tarabet, Mohand Said Lounici, Khaled Loubar, Mohand Tazerout
The use of computer engine cycle simulations, based on zero-dimensional (single zone or multi-zone) or multi-dimensional models, to aid engine systems design process has been largely applied and has become a popular tool because of combination of accurate results and reduced costs. In these models, the combustion sub-model plays a critical role in the overall engine simulation as it provides the heat release rate (HRR), which represents the combustion process for a given engine geometry and set of operating conditions. The determination of the experimental HRR is obtained solving the first law of Thermodynamics in the cylinder closed cycle with the aid of measured in-cylinder pressure. The widely used model in modern reciprocating Diesel engine applications to predict the HRR is the approximation by means of a correlation based on the combination of at least two Wiebe functions. This correlation has a characteristic S-shaped curve, which grows from zero indicating the start of combustion and tends exponentially to one indicating the end of combustion.
Technical Paper
2014-10-13
Anders Widd, Magnus Lewander
The Selective Catalytic Reduction (SCR) catalyst with ammonia as reducing agent plays a central role in today’s exhaust after-treatment systems for heavy-duty vehicles and there is a wide selection of possible catalytic materials to use. In order to facilitate the design of future catalysts, several aspects of the materials must be evaluated both in steadystate and transient operation. To this end, this paper presents a methodology for comparing the dynamic properties of different catalysts using full-size engine testing. The studied characteristics include the ammonia storage capacity, the effect on starting with an empty catalyst, the transient response to temperature gradients and changes in the urea dosing level. The temperature response is of particular importance in transient operation, where temperature increases may lead to substantial ammonia slip. A vanadium catalyst is compared to a Cu SAPO catalyst on the same substrate, and they show significant differences in their dynamic response.
Technical Paper
2014-10-13
Pawel Magryta, Miroslaw Wendeker, Adam Majczak, Michal Bialy, Ksenia Siadkowska
Nowadays more sophisticated ways are search for alternative supply of combustion engines. One of the commonly used alternative fuels is hydrogen. On the market there are quite a number of passenger cars, which are powered by hydrogen fuel. The development of this technology is primarily connected with the introduction of hydrogen refueling stations, and hydrogen storage and distribution systems. We can predict that much faster popularization trend of hydrogen fuel would bring the possibility of modifying the existing fuel supply systems of internal combustion engines for use this environmentally friendly fuel. Adaptation of existing vehicles equipped with spark-ignition engines in the ability to support combustion by dosing additional dose of hydrogen would enable the introduction of this alternative fuel on a larger scale than at present. In order to verify the assumptions of the additive supplying hydrogen, simulation test model of a spark ignition engine, developed in the AVL BOOST software was presented in the article.
Technical Paper
2014-10-13
Yufeng Li
Swirl ratio in the cylinder of a diesel engine is an important parameter for air/fuel mixing and combustion process. Swirling flow in the cylinder is formed when the intake air flows thought a helical or tangential port and inlet valve seats and then recognized by the wall of the cylinder. The swirling angular speed generated by the intake ports can be determined on a steady flow rig. The swirl ratio at the end of intake stroke in an operating engine is then estimated by equations which have already been established by Ricardo and AVL. However, the swirl ratio estimated by these existing equations is not the real value in the cylinder of an operating engine as the equations were deducted from three basic assumptions: a) volumetric efficiency of an engine is 100%; b) the pressure drop between the intake ports is constant during the engine operation; c) no burned gas residual is trapped in the cylinder. They are not true definitely. On the other hand, an accurate swirl ratio in the cylinder is essential during the engine development.
Technical Paper
2014-10-13
Jonathan Stewart, Roy Douglas, Alexandre Goguet, Cristina Elena Stere, Luke Blades
Kinetic models are becoming an ever present tool in the development of automotive catalysis, primarily used for characterisation of catalysts and as a predictive tool for performance. This has led to a large number of kinetic models related to automotive catalysis appearing in literature in literature in the past decades. Most kinetic models for automotive application focus primarily on the global kinetic approach for reaction kinetics, with the more chemically accurate micro-kinetics appearing more frequently in the past number of years. One of the most critical aspects in the development of a kinetic model in general is the method used to control the switch between limiting factors over the period of the chemical reaction, namely mass transfer and reaction kinetics. This balance becomes increasingly more critical with the automotive application as the gas composition and gas flow vary throughout the automotive cycles resulting in a large number or reactions competing, with a constantly changing space velocity.
Technical Paper
2014-10-13
Mohammad Reza Hamedi, Athanasios Tsolakis, Jose Martin Herreros
Recent developments in diesel engines lead to increased fuel efficiency and reduced exhaust gas temperature. Therefore more energy efficient aftertreatment systems are required to comply with tight emission regulations. In this study, a computational fluid dynamics package was used to investigate the thermal behaviour of diesel aftertreatment system. A parametric study was carried out to identify the most influential piping material and insulation characteristics in terms of thermal performance. In case of aftertreatment piping and canning material effect, an array of different potential materials was selected and their effects on the emission conversion efficiency of a Diesel Oxidation Catalyst (DOC) were numerically investigated over a driving cycle. Results indicate that although the piping material volumetric heat capacity was decreased by a factor of four, the total emission reduction was only considerable during the cold start. Since the piping system heat up and cool down periods were accelerated by reducing the system thermal inertia.
Technical Paper
2014-10-13
Karthik Puduppakkam, Chitralkumar Naik, Ellen Meeks, Christian Krenn, Roswitha Kroiss, Johannes Gelbmann, Guenther Pessl
An important goal for CFD simulation in engine design is to be able to predict the combustion behavior as operating conditions are varied and as hardware is modified. Such predictive capability allows virtual prototyping and optimization of design parameters. For low-temperature combustion conditions, such as with high rates of exhaust-gas recirculation, reliable and accurate predictions have been elusive. Soot has been particularly difficult to predict, due to the dependence of soot formation on the fuel composition and the kinetics detail of the fuel combustion. Soot evolution in diesel engines is impacted by fuel and chemistry effects, as well as by spray dynamics and turbulence. In this work, we present a systematic approach to accurately simulate combustion and emissions in a high-performance BMW diesel engine. This approach has been tested and validated against experimental data for a wide range of operating conditions. Nine operating conditions have been modeled that span engine loads of 3-21 bar MEP, engine speeds of 1000-4400 rpm and external EGR of 0-38%.
Technical Paper
2014-10-13
Trevor Crain, Michael Ryan Mallory, Megan Cawley, Brian Fabien, Per Reinhall
This paper details the control system development process for the University of Washington (UW) EcoCAR 2 team over the three years of the competition. Particular emphasis is placed upon the control system development and validation process executed during Year 3 of the competition in an effort to meet Vehicle Technical Specifications (VTS) established and refined by the team. The EcoCAR 2 competition challenges 15 universities across North America to reduce the environmental impact of a 2013 Chevrolet Malibu without compromising consumer acceptability. The project takes place over a three year design cycle, where teams select a hybrid architecture and fuel choice before defining a set of VTS goals for the vehicle. These VTS are selected based on the desired static and dynamic performance targets to balance fuel consumption and emissions with consumer acceptability requirements. The UW team selected a Parallel through the Road hybrid architecture due to its combination of performance capabilities, high power path efficiency, and reliability due to separated electric and biodiesel powertrains.
Technical Paper
2014-10-13
P. Christopher Manning, Eduardo D. Marquez, Leonard Figueroa, Douglas J. Nelson, Eli Hampton White, Lucas Wayne Shoults
The Hybrid Electric Vehicle Team (HEVT) of Virginia Tech is ready to compete in the Year 3 Final Competition for EcoCAR 2: Plugging into the Future. The team is confident in the reliability of their vehicle, and expects to finish among the top schools at Final Competition. During Year 3, the team refined the vehicle while following the EcoCAR 2 Vehicle Development Process (VDP). Many refinements came about in Year 3 such as the implementation of a new rear subframe, the safety analysis of the high voltage (HV) bus, and the integration of Charge Sustaining (CS) control code. HEVT’s vehicle architecture is an E85 Series-Parallel Plug-In Hybrid Electric Vehicle (PHEV), which has many strengths and weaknesses. The primary strength is the pure EV mode and Series mode, which extend the range of the vehicle and reduce Petroleum Energy Usage (PEU) and Greenhouse Gas (GHG) emissions. A primary weakness is its complexity, which made it difficult for the team to truly reap the benefits of the added components to the vehicle which are utilized in Parallel mode.
Technical Paper
2014-10-13
Thomas Bradley, Benjamin Geller, Jake Bucher, Shawn Salisbury
EcoCAR 2 is the premiere North American collegiate automotive competition that challenges 15 North American universities to redesign a 2013 Chevrolet Malibu to decrease the environmental impact of the Malibu while maintaining its performance, safety, and consumer appeal. The EcoCAR 2 project is a three year competition headline sponsored by General Motors and U.S. Department of Energy. In Year 1 of the competition, extensive modeling guided the Colorado State University (CSU) Vehicle Innovation Team (VIT) to choose an all-electric vehicle powertrain architecture with range extending hydrogen fuel cells, to be called the Malibu H2eV. During this year, the CSU VIT followed the EcoCAR 2 Vehicle Design Process (VDP) to develop the H2eV’s electric and hydrogen powertrain, energy storage system (ESS), control systems, and auxiliary systems. From the design developed in Year 1 of the EcoCAR 2 competition, a Malibu donated by General Motors was converted into a concept validating prototype during Year 2.
Technical Paper
2014-10-13
Sophie Porter, Ahmad Kamal Mat Yamin, Svetlana Aleksandrova, Stephen Benjamin, Carol A. Roberts, Jonathan Saul
Flow maldistribution across automotive exhaust catalysts significantly affects their conversion efficiency. This study investigates the application of CFD in modelling flow in a 2D rig consisting of a catalyst monolith downstream of a wide-angled planar diffuser presented with steady flow. Two distinct approaches, porous medium and individual channels, are used to model monoliths of length 27mm and 100mm. Flow predictions are compared to particle image velocimetry (PIV) measurements made in the diffuser and hot wire anemometry (HWA) data taken downstream of the monolith. Upstream of the monolith, the two CFD approaches agree well for velocity profiles across the central jet. CFD predictions diverge outside of this area, with neither one markedly closer to PIV results. Modelling the monolith as a fluid region of individual channels is shown to improve the prediction of flow maldistribution downstream of the monolith when compared to the porous medium approach. The individual channels model also predicts height and placement of secondary peaks closer to those of HWA data.
Viewing 1 to 30 of 29350