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Viewing 1 to 30 of 106972
2016-05-05
Journal Article
2015-01-9148
Saeed Asgari, Shailendra Kaushik
Abstract A linear parameter varying (LPV) reduced order model (ROM) is used to approximate the volume-averaged temperature of battery cells in one of the modules of the battery pack with varying mass flow rate of cooling fluid using uniform heat source as inputs. The ROM runs orders of magnitude faster than the original CFD model. To reduce the time it takes to generate training data, used in building LPV ROM, a divide-and-conquer approach is introduced. This is done by dividing the battery module into a series of mid-cell and end-cell units. A mid-cell unit is composed of a cooling channel sandwiched in between two half -cells. A half-cell has half as much heat capacity as a full-cell. An end-cell unit is composed of a cooling channel sandwiched in between full-cell and a half-cell. A mass flow rate distribution look-up-table is generated from a set of steady-state simulations obtained by running the full CFD model at different inlet manifold mass flow rate samples.
2016-05-01
Journal Article
2015-01-9146
Swanand Kulkarni
In a Mild hybrid electric vehicle, a battery serves as a continuous source of energy but is inefficient in supplying peak power demands required during torque assists for short duration. Moreover, the random charging and discharging that result due to varying drive cycle of the vehicle affects the life of the battery. In this paper, an Ultra-capacitor based hybrid energy storage system (HESS) has been developed for mild hybrid vehicle which aims at utilizing the advantages of ultra-capacitors by combining them with lead-acid batteries, to improve the overall performance of the battery, and to increase their useful life. Active current-sharing is achieved by interfacing ultra-capacitor to the battery through a bi-directional boost dc-dc converter.
2016-05-01
Journal Article
2015-01-9145
Abdullah AL-Refai, Osamah Rawashdeh, Rami Abousleiman
Abstract Lithium-Ion batteries are the standard portable power solution to many consumers and industrial applications. These batteries are commonly used in laptop computers, heavy duty devices, unmanned vehicles, electric and hybrid vehicles, cell phones, and many other applications. Charging these batteries is a delicate process because it depends on numerous factors such as temperature, cell capacity, and, most importantly, the power and energy limits of the battery cells. Charging capacity, charging time and battery pack temperature variations are highly dependent on the charging method used. These three factors can be of special importance in applications with strict charging time requirements or with limited thermal management capabilities. In this paper, three common charging methods are experimentally studied and analyzed. Constant-current constant-voltage, the time pulsed charging method, and the multistage constant current charging methods were considered.
2016-05-01
Journal Article
2015-01-9147
Zhiyun Zhang, Miaohua Huang, Yupu Chen, Shuanglong Zhu
Abstract In the field of Electric Vehicle (EV), what the driver is most concerned with is that whether the value of the battery's capacity is less than the failure threshold because of the degradation. And the failure threshold means instability of the battery, which is of great danger for drives and passengers. So the capacity is an important indicator to monitor the state of health (SOH) of the battery. In laboratory environment, standard performance tests can be carried out to collect a number of related data, which are available for regression prediction in practical application, such as the on-board battery pack. Firstly, we make use of the NASA battery data set to form the observed data sequence for regression prediction. And a practical method is proposed to determine the minimum embedding dimension and get the recurrence formula, with which a capacity model is built.
2016-05-01
Journal Article
2015-01-9132
Husain Kanchwala, Harutoshi Ogai
Abstract Japan is suffering from the problem of an ageing society. In Kitakyushu city more than a quarter of people are aged above 65 years. The roads in this region are narrow with steep gradient and vulnerable roadbed. A big ratio of elderly people are living on their own. These characteristics make driving unsuitable. The problem is magnified by infrequent public transportation. A need-assessment survey for an autonomous vehicle at a community event suggested the applicability of small electric vehicle Toyota COMS. The vehicle is then equipped with features like automatic driving and platooning. The autonomous drive system is built to develop an intelligent transport system (ITS) using various sensors and actuators. Stereo camera and ultrasonic sensors were used to get a judgment of obstacle. Google earth and GPS were used to generate the target path using the Bezier curve method and optimized route is chosen.
2016-05-01
Journal Article
2015-01-9144
Marc-Olivier Lacerte, Gabriel Pouliot, Jean-Sébastien Plante, Philippe Micheau
Electric Vehicles (EVs) with single-ratio gearbox provide high levels of smoothness, but using multi-speed gearbox can provide significant benefits in terms of vehicle acceleration, top speed, powertrain cost, mass, and energy consumption. In particular, Automated Manual Transmissions (AMTs) have characteristics of smooth shifts without torque interruption when coupled to a torque bypass clutch. However, conventional friction clutches are not best suited as torque bypass clutches because of their limited controllability and because large amount of heat must be dissipated to slow down the motor during gearshifts. This paper studies the feasibility of a seamless AMT architecture for EVs and Hybrid Electric Vehicles (HEVs) using an eddy current torque bypass clutch that is highly controllable, robust, low cost, and has no wearable parts.
2016-04-15
Journal Article
2015-01-9020
Emre Sert, Pinar Boyraz
Abstract Studies have shown that the number of road accidents caused by rollover both in Europe and in Turkey is increasing [1]. Therefore, rollover related accidents became the new target of the studies in the field of vehicle dynamics research aiming for both active and passive safety systems. This paper presents a method for optimizing the rear suspension geometry using design of experiment and multibody simulation in order to reduce the risk of rollover. One of the major differences of this study from previous work is that it includes statistical Taguchi method in order to increase the safety margin. Other difference of this study from literature is that it includes all design tools such as model validation, optimization and full vehicle handling and ride comfort tests. Rollover angle of the vehicle was selected as the cost function in the optimization algorithm that also contains roll stiffness and height of the roll center.
2016-04-05
Journal Article
2015-01-9152
André Lundkvist, Arne Nykänen, Roger Johnsson
Abstract Many of the information systems in cars require visual attention, and a way to reduce both visual and cognitive workload could be to use sound. An experiment was designed in order to determine how driving and secondary task performance is affected by the use of information sound signals and their spatial positions. The experiment was performed in a driving simulator utilizing Lane Change Task as a driving scenario in combination with the Surrogate Reference Task as a secondary task. Two different signal sounds with different spatial positions informed the driver when a lane change should be made and when a new secondary task was presented. Driving performance was significantly improved when both signal sounds were presented in front of the driver. No significant effects on secondary task performance were found. It is recommended that signal sounds are placed in front of the driver, when possible, if the goal is to draw attention forward.
2016-04-05
Journal Article
2015-01-9153
André Lundkvist, Arne Nykänen
Abstract The number of advanced driver assistance systems is constantly increasing. Many of the systems require visual attention, and a way to reduce risks associated with inattention could be to use multisensory signals. A driver's main attention is in front of the car, but inattention to surrounding areas beside and behind the car can be a risk. Therefore, there is a need for driver assistance systems capable of directing attention to the sides. In a simulator study, combined visual, auditory and vibrotactile signals for directional attention capture were designed for use in driver assistance systems, such as blind spot information, parking assistance, collision warnings, navigation, lane departure warning etc. An experiment was conducted in order to measure the effects of the use of different sensory modalities on directional attention (left/right) in driver assistance systems.
2016-04-05
Technical Paper
2016-01-0798
Ravichandra S. Jupudi, Charles E.A. Finney, Roy Primus, Sameera Wijeyakulasuriya, Adam E. Klingbeil, Bhaskar Tamma, Miroslav K. Stoyanov
Cost- and emissions-reduction pressures are driving engine manufacturers to consider fuel substitution in heavy-duty diesel internal combustion engines. One promising application is that of large-bore, medium-speed engines such as those used in locomotives. These engines could be operated either in diesel-only mode or operated with premixed natural gas ignited by a pilot flame of compression-ignited direct-injected diesel fuel. With realistic natural gas substitution levels in the fleet of locomotives currently in service, such fuel substitution could result in billions of dollars of savings annually in the US alone. However, under certain conditions, dual-fuel operation can give rise to unstable combustion, resulting in cyclic variations in cylinder pressure and work extraction. In certain situations, the CCV of dual-fuel operation can be notably higher than that of diesel-only combustion under similar operating conditions.
2016-04-05
Technical Paper
2016-01-0782
Chaitanya Kavuri, Sage Kokjohn
Past research has shown that reactivity controlled compression ignition (RCCI) combustion offers efficiency, NOx and soot advantages over conventional diesel combustion at mid load conditions. However, at high load and low speed conditions, the chemistry time scale of the fuel shortens and the engine time scale lengthens. This mismatch in chemistry and engine timescales makes operation at high load and low speed conditions difficult. High levels of exhaust gas recirculation (EGR) can be used to extend the chemistry timescales; however, this comes at the penalty of increased pumping losses. In the present study, targeting the high load – low speed regime, computational optimizations of dual fuel RCCI combustion were performed at 20 bar gross indicated mean effective pressure (IMEP) and 1300 rev/min. The two fuels used for the study were gasoline (low reactivity) and diesel (high reactivity). The effects of intake pressure and EGR on combustion and emissions were studied.
2016-04-05
Technical Paper
2016-01-0771
Silvana Di Iorio, Agnese Magno, Ezio Mancaruso, Bianca Maria Vaglieco
Methane is a promising fuel for internal combustion engine because of its environmental friendly characteristics and renewable nature. It can be used in existing compression ignition engine through dual fuel technology. This paper deals with the combustion characteristics and exhaust emissions of a small compression ignition engine modified to operate in diesel/methane dual fuel mode. The engine is a three-cylinder, 1028 cc of displacement, equipped with a common rail injection system and a diesel oxidation catalyst. A gas injector was set up in the intake manifold and it was managed by an external delay unit. Experiments were carried out at different engine speeds and loads. For each engine operating conditions, a part of the total load was supplied by the diesel combustion and the remaining by methane. Thermodynamics analysis of the combustion phase was performed by in-cylinder pressure signal.
2016-04-05
Technical Paper
2016-01-0632
Domenico Crescenzo, Viktor Olsson, Javier Arco Sola, Hongwen Wu, Andreas Cronhjort, Eric Lycke, Oskar Leufven, Ola Stenlaas
Due to demanding legislation on exhaust emissions for internal combustion engines and increasing fuel prices, automotive manufacturers have focused their efforts on optimizing turbocharging systems. Turbocharger system control optimization is difficult: Unsteady flow conditions combined with not very accurate compressor maps make the real time turbocharger rotational speed one of the most important quantities in the optimization process. This work presents a methodology designed to obtain the turbocharger rotational speed via vibration analysis. Standard knock sensors have been employed in order to achieve a robust and accurate, yet still a low-cost solution capable of being mounted on-board. Results show that the developed method gives an estimation of the turbocharger rotational speed, with errors and accuracy acceptable for the proposed application. The method has been evaluated on a heavy duty diesel engine.
2016-04-05
Technical Paper
2016-01-0674
Macklini Dalla Nora, Thompson Lanzanova, Yan Zhang, Hua Zhao
With the introduction of fuel economy or CO2 emissions legislation in Europe and many countries, there has been extensive research on developing high efficiency gasoline engines by means of the downsizing technology. Engine downsizing is typically achieved by combining direct fuel injection, variable valve actuation, boosting technologies and improved quality fuels in four-stroke poppet valve engines. Under this approach the engine operation is shifted towards higher load regions where pumping and friction losses have a reduced effect, so improved efficiency is achieved with smaller displacement engines. However, to ensure the same full load performance of larger engines the charge density needs to be increased, which raises concerns about structural stresses and abnormal combustion at high in-cylinder pressures.
2016-04-05
Technical Paper
2016-01-0697
Francesco Catapano, Silvana Di Iorio, Ludovica Luise, Paolo Sementa, Bianca Maria Vaglieco
Even more attention was paid to the direct injection (DI) system in spark ignition (SI) engines. DI allows to achieve improved efficiency. Nevertheless, the less time for fuel evaporation and mixing with respect to PFI engines as well as the larger fuel impingement, results in larger HC and CO emissions as well as particle emissions. PFI SI engine are characterized by low exhaust emissions but at the same time by lower engine performance. In this paper was investigated the effect of the O2 addition on engine performance and emissions. The experimental investigation was carried out in a small single-cylinder, PFI SI four-stroke engine. The engine emissions were characterized by means of gaseous analyzers and a smokemeter. Particle size distribution function was measured in the size range from 5.6 to 560 nm by means of an Engine Exhaust Particle Sizer (EEPS). The investigation was carried out at different engine speeds.
2016-04-05
Technical Paper
2016-01-0647
Azmi Osman, M. Khairul Arif Muhammad Yusof, Mohammad Rafi
Additional fuel consumption reduction during the NEDC test cycle and real life driving can be effectively achieved by quickly raising the temperatures of the powertrain’s parts, oils and coolant closer to the optimal operating temperatures. In particular, the engine cooling system today must play a bigger role in the overall thermal management of the powertrain’s fluids and metals during warm-up, idle and severe operating conditions. In responding to these additional requirements, the previously proposed cost effective split cooling system has been further evolved to expedite the powertrain’s warming up process without compromising the overall heat rejection performance during severe operating conditions. In achieving these warming and cooling functions, the coolant flow rate in the cylinder head is almost stagnant when the single thermostat is closed and at its maximum when the thermostat is fully opened.
2016-04-05
Technical Paper
2016-01-0735
J. Javier Lopez, Jaime Martin, Antonio Garcia, David Villalta, Alok Warey, Vicent Domenech
Engine-out soot emissions are the result of a complex balance between in-cylinder soot formation and oxidation. Soot is formed in the diffusion flame, just after the lift-off length. Size and mass of soot particles increases through the diffusion flame and finally they are partially oxidized at the flame front. Therefore, engine-out soot emissions depend on the amount of soot formed and oxidized inside the combustion chamber. There is a considerable amount of work in the literature on characterization of soot formation. However, there is a clear lack of published research related to the characterization of soot oxidation. Thus, the main objective of the current research is to provide more knowledge and insight into the soot oxidation processes. For this purpose, a combination of theoretical and experimental tools were used. In particular, in- cylinder optical thickness (KL) was quantified with an optoelectronic sensor that uses two-color thermometry.
2016-04-05
Technical Paper
2016-01-0739
Senthilkumar Masimalai, Sasikumar Nandagopal, Venkatesan Kuppusamy
This paper aims at studying the effect of oxygen enriched combustion on performance, emission and combustion characteristics of a diesel engine using the blend of Pyro oil obtained from pyrolysis of cashew nut shell and conventional diesel as fuel. A single cylinder water-cooled, agricultural purpose, direct injection diesel engine was used. The intake system of the engine was modified to accommodate excess oxygen in the incoming air. A separate oxygen cylinder was used for storing pure oxygen and supplying it along with intake air. Base line data was generated using diesel as fuel. Subsequently experiments were repeated with the blend of 40% of Cashew nut shell oil and 60% diesel by volume (called CSO40D60) at different oxygen concentrations such as 21%, 22% 23%, 24% and 25% in the intake air. Engine performance, emission and combustion parameters were obtained at different power outputs and analyzed.
2016-04-05
Technical Paper
2016-01-0877
Preetham Churkunti, Jonathan M. S. Mattson, Christopher Depcik
Biodiesel derived from Waste Cooking Oil (WCO) has gradually become more competitive in comparison to diesel (ULSD), but suffers from increased fuel consumption without calibration to change injection timings or pressures. Increasing biodiesel injection pressure has been found to mitigate problems associated with the high viscosity of biodiesel, decreasing fuel consumption. In addition, literature indicates increasing fuel injection pressure with biodiesel may be associated with decreased emissions (particularly NOx emissions). This study explores the usage of ULSD, WCO biodiesel, and their blends, with injection pressure adjustment in a single-cylinder diesel engine. Fuel injection pressures and timings for WCO biodiesel and blended fuels are adjusted to bring about combustion that mimics the in-cylinder pressure profile of operation with ULSD.
2016-04-05
Technical Paper
2016-01-0933
Steve Golden, Zahra Nazarpoor, Maxime Launois, Ru-Fen Liu, Pardha Maram
In the context of evolving market conditions, the Three-Way Catalyst (TWC) is entering an exciting new phase. It remains the main emission control strategy for gasoline powered vehicles but a period of rapidly evolving engine development, constrained tailpipe regulations and material supply issues present a unique challenge to catalyst developers. In this regard, CDTi is mainly focused on design and development of copper-free spinel oxide based Zero-precious metal (ZPGM) and spinel synergized precious metal (SPGM) with ultra-low presence of PGM to achieve highly beneficial emission performance improvements. The copper-free transition metal based spinel ZPGM catalysts shows improved thermal stability and redox reversibility compared to the copper based ZPGM materials. Fundamental studies of microstructure of spinel by high resolution TEM confirmed the aging stability of new developed spinel composition.
2016-04-05
Technical Paper
2016-01-1119
Prashant Jha
The Concept of Automatic Transmission is ubiquitous and ever increasing as they offer an ease of operation. Implementation of automatic Transmission in manual gear boxes however is relatively new. Based on Fuzzy Logic a Shift Schedule has been developed for Automatic Manual Transmission (AMT), to estimate various loads and resistances incurred by road Gradients and Loading conditions. A Shift Schedule has been designed in accordance with vehicle speed, road loads and throttle valve opening. This will ultimately result in an automatic gear box with improvement in shift quality and prudent Gear shift irrespective of rider competence. This Shift Schedule control method significantly reduces Gear hunting at variable gradients and at different loading conditions.
2016-04-05
Technical Paper
2016-01-1120
Dong Guo, Quan Shi, Peng Yi
Gear drives are widely used in the transmission of many types of vehicles and various gear faults were reported to have different effects on the performance of transmission systems. The psychoacoustics metrics, which are used to represent the human hearing property, are objective indicators of product sound quality performance. Therefore, psychoacoustic analysis of gear noise with gear faults needs to be conducted. In this paper, different types of gear faults are summarized, and three of them, including wear, misalignment and eccentricity, are studied separately in the psychoacoustic analysis of the synthesized noise signal of an example gearbox. The gear noise spectra for the cases with different gear faults are synthesized based on the findings of previous publications, where it shows that the three gear faults can either increase the amplitude at the harmonics of the gear mesh frequency or cause the sideband responses.
2016-04-05
Technical Paper
2016-01-1109
Okumura Naotoshi
Transmission structure and specifications ・Technology for transmission efficiency improvement ・Development of new control to improve drivability A new generation CVT with auxiliary gear box has been developed and started to be sold in the market. It has wider ratio coverage than previous generation and lower friction realized by several technologies, such as hydraulic control system improvement, oil pump loss reduction, friction reduction of ball bearing with seal , and some other technologies. Ratio shifting control and auxiliary gear box shifting control has been improved and newly developed controls are also introduced together with torque converter lock up clutch control improvement . Those new controls improved vehicle drivability and performance. In this presentation, the outline of the new generation CVT with auxiliary gear box will be explained and topics of new technologies will also be highlighted.
2016-04-05
Technical Paper
2016-01-1050
Vikas V Thorat, Girish Khairnar, Saurav Chatterjee, Jagrit Shrivas, Vishwakarma Diwakar, Sandip Chaudhari
In India, there is a constant rise in demand for three wheelers as they are cheap and convenient mode of transport and also suitable for heavy city traffic & narrow roads due to their small and modular vehicle structure. From last few decades, Greaves is playing a major role in providing single cylinder engines (Diesel/ CNG) for three wheelers in the market. In view of the changing dynamics of fuel prices in India, where the gap between diesel and petrol prices are shrinking, people are once again shifting their preferences towards the gasoline vehicles to en-cash a better cost advantage as compared to diesel vehicles. By considering this market Scenario, Greaves has developed dedicated Gasoline engine compliance with BS-III emission norms for three wheeler application. In the era of electronization, demand for electrical auxiliaries on engine is considerably expanding. To cater to this requirement, higher output Flywheel mounted alternator (FMA) is explored and introduced.
2016-04-05
Technical Paper
2016-01-1055
Ashwini Agarwal, Andrew Lewis, Sam Akehurst, Chris Brace, Yash Gandhi, Gary Kirkpatrick
Range extended electric vehicles (REEV) are gaining popularity due to their simplicity, reduced emissions and fuel consumption when compared to parallel or series/parallel hybrid vehicles. The range extender ICE can be optimised to a number of steady state points which offers significant improvement in overall exhaust emissions. One of the key challenges in such vehicles is to reduce the overall powertrain costs, and OEMs providing REEVs such as the BMW i3 have included the range extender as an optional extra due to increasing costs on the overall vehicle price. This paper discusses the development of a low cost auxiliary power unit (APU) for the range extender application utilising a well optimised production automotive two cylinder gasoline engine. The 624 cc production engine was further optimised given the project constraints of low cost changes to suit a range extender application.
2016-04-05
Technical Paper
2016-01-1056
Vikas Kolage, Santosh Madireddy
The heart and soul of any fuel based automobile is its engine, which forms the powerhouse generating energy required for movement. Since its inception, it forms the most crucial part of any vehicle. It is therefore safe to say that necessity driven innovations are aimed at engine and its related components than any other aggregate of an automobile. The laws of physics which provide this power also constraint the applicability of engines in automobiles. Due to the oscillating motion generated inside cylinders, forces of imbalance are prevalent throughout the mechanism. While primary forces are usually done and dealt by placing counterweights on crankshaft, secondary forces are eliminated through various different accepted measures. The elimination of imbalances isn’t enough to reduce the shake of an engine and hence we need Engine Mounts for this purpose. They absorb the vibrations produced and eliminate chances of coupling and superposition.
2016-04-05
Technical Paper
2016-01-1014
Shyam K. Menon, Himakar Ganti, Chris Hagen
Natural gas is an attractive option for transportation applications in the United States due to its abundant availability and potential for reduced emissions. The scarcity of refueling resources imposes a barrier to widespread use of natural gas in internal combustion engines. A novel bi-modal engine under development is capable of operating in a compressor mode and provide refueling capabilities without any supplemental devices thus overcoming the infrastructure based limitations. As part of this development, a multi-cylinder production engine was acquired and its intake modified to allow for one cylinder to perform compression. This system was tested with accompanying plate heat exchangers that allow for cooling of the compressed gas.
2016-04-05
Technical Paper
2016-01-1177
Aditya Dhand, Keith Pullen
There are different types of energy storage devices which are used in today’s hybrid and electric vehicles. Batteries, ultra capacitors and high speed flywheels are the most commonly used ones. While batteries and supercapacitors store energy in the form of electric energy, the flywheel (FW) is the only device that keeps the energy stored in the original form of mechanical energy the same as the moving vehicle. The flywheel needs to be coupled to the driveshaft of the vehicle in a manner which allows it to vary its speed independently of the moving vehicle in order to vary its energy content. In other words a continuously variable transmission (CVT) is needed. The common mechanical variators used in automotive applications, namely the rolling traction drives and the belt drives, have the disadvantage that their speed ratio range defined as the maximum to minimum speed ratio is generally not sufficient for flywheel energy storage system (FESS).
2016-04-05
Technical Paper
2016-01-0447
Manfred Baecker, Axel Gallrein, Francesco Calabrese, Remco Mansvelders
A sudden pressure loss can lead to an instability of the car. This instability can lead - without aid of systems such as e.g. Electronic Stability Control (ESC) - to an emergency situation, possibly resulting in an accident. But also with an ESC system such a situation is an unusual application case, because the vehicle system (car+tires) properties change very rapidly, resulting in a highly dynamic response of the system and moreover to a fuzzy and unclear description of the vehicle system. From this point of view, a proper validation and verification of an ESC system for such an application seems to have a big safety relevance. The authors have set up a simulation case to simulate a sudden tire inflation pressure loss and its consequences to the car stability. Using this simulation setup enables a CAE engineer to pre-develop ESC systems and/or to validate and test these systems for a realistic and relevant use case.
2016-04-05
Technical Paper
2016-01-0446
Chen liang, Guolin Wang, Zhou Zheng
A three-dimensional finite element model of radial tire 205/55R16,established by ABAQUS software,is used to simulate tire force and moment properties. Drum tests are designed to validate the simulation model’s reliability. To investigate the impacts of PCR contour design theory on tire force and moment, a modified string balance contour theory is presented, based on string balance contour theory, which simplifies the belts pressure share ratio as trapezium. And a program for calculating tire’s contour is compiled. Different tire contours are designed according to different belt pressure share ratios. One of the contours is selected according to the positive affect to cornering stiffness. Compare the selected newly designed tire with the original one, it is found that the newly designed tire’s contact area, longitudinal stiffness,lateral stiffness,camber stiffness and cornering stiffness increase while its radial stiffness decreases.
Viewing 1 to 30 of 106972