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Hybrid Powertrain Technology Assessment through an Integrated Simulation Approach

University Of Bath-Yang Liu
Continental-Naroa Zaldua-Moreno, Lorenzo Pace
Published 2019-09-09 by SAE International in United States
Global automotive fuel economy and emissions pressures mean that 48 V hybridisation will become a significant presence in the passenger car market. The complexity of powertrain solutions is increasing in order to further improve fuel economy for hybrid vehicles and maintain robust emissions performance. However, this results in complex interactions between technologies which are difficult to identify through traditional development approaches, resulting in sub-optimal solutions for either vehicle attributes or cost. The results presented in this paper are from a simulation programme focussed on the optimisation of various advanced powertrain technologies on 48 V hybrid vehicle platforms. The technologies assessed include an electrically heated catalyst, an insulated turbocharger, an electric water pump and a thermal management module. The novel simulation approach undertaken uses an integrated toolchain capturing thermal, electrical and mechanical energy usage across all powertrain sub-systems. Through integrating 0-D and 1-D sub-models into a single modelling environment, the operating strategy of the technologies can be optimised while capturing the synergies that exist between them. This approach enables improved and more informed cost/benefit ratios for…
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Comparison of 1-D Modelling Approaches for Wankel Engine Performance Simulation and Initial Study of the Direct Injection Limitations

University Of Bath-Michael Peden, Matthew Turner, James W G Turner
Advanced Innovative Engineering UK Ltd-Nathan Bailey
Published 2018-04-03 by SAE International in United States
Recent interest in the possible use of Wankel engines as range extenders for electric vehicles has prompted renewed investigations into the concept. While not presently used in the automotive industry, the type is well established in the unmanned aerial vehicles industry, and several innovative approaches to sealing and cooling have recently been developed which may result in improved performance for ground vehicle applications.One such UAV engine is the 225CS, a 225 cc/chamber single-rotor engine manufactured by Advanced Innovative Engineering (UK) Ltd. To be able to analyse the parameters, opportunities and limitations of this type of engine a model was created in the new dedicated Wankel modelling environment of AVL BOOST. For comparison a second model was created using the established method of modelling Wankel engines by specifying an ‘equivalent’ 3-cylinder 4-stroke reciprocating engine. The output from both of these models was evaluated using engine test data supplied by Advanced Innovative Engineering (UK) Ltd. The model created in the dedicated Wankel environment was found to fit the experimental data more closely.The model was then used to…
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Distance Estimation by Fusing Radar and Monocular Camera with Kalman Filter

Yuxiang Feng
University Of Bath-Simon Pickering, Edward Chappell, Pejman iravani PhD, Chris Brace
Published 2017-09-23 by SAE International in United States
The major contribution of this paper is to propose a low-cost accurate distance estimation approach. It can potentially be used in driver modelling, accident avoidance and autonomous driving. Based on MATLAB and Python, sensory data from a Continental radar and a monocular dashcam were fused using a Kalman filter. Both sensors were mounted on a Volkswagen Sharan, performing repeated driving on a same route. The established system consists of three components, radar data processing, camera data processing and data fusion using Kalman filter. For radar data processing, raw radar measurements were directly collected from a data logger and analyzed using a Python program. Valid data were extracted and time stamped for further use. Meanwhile, a Nextbase monocular dashcam was used to record corresponding traffic scenarios. In order to measure headway distance from these videos, object depicting the leading vehicle was first located in each frame. Afterwards, the corresponding vanishing point was also detected and used to automatically compute the camera posture, which is to minimize the interference caused by camera vibration. The headway distance can…
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An Investigation Into the Port Timing of a Burt-McCollum Sleeve Valve and Its Interaction with a Simple Variable Compression Ratio Mechanism

University Of Bath-James W.G. Turner, James P. Lewis Monsma
Published 2017-09-04 by SAE International in United States
Modern automotive engines almost exclusively operate on the 4-stroke Otto cycle and utilize poppet valves for gas exchange. This state of affairs has not always been the case, however, and one unusual and relatively successful technology that was once in mass production (albeit in piston aero engines) was the Burt-McCollum single sleeve valve. This paper investigates the timing and angle-area of a Bristol Centaurus engine cylinder, which utilized such a single sleeve valve for gas exchange, using some modern tools. A comparison with poppet valve angle-areas is made. Finally, the results are also used to study the potential of variable valve timing and the interaction with variable compression ratio of a single sleeve mechanism.An opportunity for the sleeve valve is provided by the fact that direct injector placement in the cylinder junk head is effectively completely free, and furthermore multiple ignition sites can be incorporated to increase the delivered ignition energy for dilute mixtures, for example. Furthermore, as there are no mechanical impact loads (as arise from poppet valves hitting their seats, for instance), theoretically…
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Chassis Dynamometer Testing: Addressing the Challenges of New Global Legislation

Eduardo Galindo
University Of Bath-Chris J. Brace, Edward Chappell
  • Book
  • R-452
Published 2017-06-29 by SAE International in United States

The use of the chassis dynamometer test cells has been an integral part of the vehicle development and validation process for several decades, involving specialists from different fields, not all of them necessarily experts in automotive engineering.

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Influence of Coolant Temperature and Flow Rate, and Air Flow on Knock Performance of a Downsized, Highly Boosted, Direct-Injection Spark Ignition Engine

University Of Bath-Andrew Lewis, Sam Akehurst
University of Bath-Mohd Asif, Karl Giles
Published 2017-03-28 by SAE International in United States
The causes of engine knock are well understood but it is important to be able to relate these causes to the effects of controllable engine parameters. This study attempts to quantify the effects of a portion of the available engine parameters on the knock behavior of a 60% downsized, DISI engine running at approximately 23 bar BMEP. The engines response to three levels of coolant flow rate, coolant temperature and exhaust back pressure were investigated independently. Within the tested ranges, very little change in the knock limited spark advance (KLSA) was observed. The effects of valve timing on scavenge flow and blow through (the flow of fresh air straight into the exhaust system during the valve overlap period) were investigated at two conditions; at fixed inlet/exhaust manifold pressures, and at fixed engine torque. For both conditions, a matrix of 8 intake/exhaust cam combinations was tested, resulting in a wide range of valve overlap conditions (from 37 to -53°CA). The results indicate that at the fixed manifold pressure test condition, the effects of cam timing on…
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DigitalAir Camless FVVA System - Part 2, Gasoline Engine Performance Opportunities

SAE International Journal of Engines

University Of Bath-James W.G. Turner, Roshan S. Wijetunge
Anderson Consulting-William Anderson
  • Journal Article
  • 2017-01-0641
Published 2017-03-28 by SAE International in United States
The paper describes a completely new approach to fully variable valve actuation (FVVA), which allows almost unlimited continuously variable control of intake and exhaust valve opening and closing events, and duration without the use of a camshaft.DigitalAir replaces conventional poppet valves with horizontally actuated valves located directly above the combustion deck of the cylinder head, which open and close a number of slots connecting the cylinder with the intake and exhaust ports, Figure 1. The stroke of the valves to provide the full flow area is approximately 25% of the stroke of the equivalent poppet valve, thus allowing direct electrical actuation with very low power consumption. This design arrangement also avoids the risk of poppet valve to piston collision, or the need for cut-outs in the piston crown, since the valves do not open into the cylinder.The paper will present analytical and experimental data which confirms that the proposed FVVA system can meet the basic performance requirements of modern GDI engines with respect to breathing characteristics across the speed range, throttleless operation at and above…
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RETRACTION: Durability Loads Prediction of Body-on-Frame Vehicles using Full Vehicle Simulations

University Of Bath-Jos Darling
Christian Scheiblegger Consulting-Christian Scheiblegger
Published 2017-03-14 by SAE International in United States
Paper withdrawn by author.
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Explore and Extend the Effectiveness of Turbo-Compounding in a 2.0 Litres Gasoline Engine (Second Report: Fuel Economy under Part Load Condition, Transient Performance and Effect of Pressure Ratio)

University Of Bath-Pengfei Lu, Chris Brace, Bo Hu
Published 2016-04-05 by SAE International in United States
The turbo-compounding has been extensively researched as a mean of improving the overall thermal efficiency of the internal combustion engine. Many of the studies aiming to optimize the turbo-compounding system lead to the unified conclusion that this approach is more suitable for the operation under constant high load condition, while it has little effect on improving the fuel economy under low load conditions. Besides, in a traditional series turbo-compounding engine, the increased back pressure unavoidably results in a serious parasitic load to the system by increasing the resistance to the scavenging process. In order to improve this situation, a novel turbo-compounding arrangement has been proposed, in which the turbocharger was replaced by a continuously variable transmission (CVT) coupled supercharger (CVT superchargedr) to supply sufficient air mass flow rate to the engine at lower engine speeds. The exhaust was directed to the power turbine that converted the waste heat into useful mechanical work and fed it to the crankshaft. According to the results, the CVT superchargedr helped to increase the brake torque by up to 24%…
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SuperGen - A Novel Low Costs Electro-Mechanical Mild Hybrid and Boosting System for Engine Efficiency Enhancements

University Of Bath-James Turner
Integral Powertrain, Ltd.-Jason King, Luke Barker, John Martin
Published 2016-04-05 by SAE International in United States
SuperGen is a Belt Integrated Starter Generator (B-ISG) combined with a novel electro-mechanical power split transmission system providing variable speed centrifugal supercharger capability, all in one compact package. This paper initially discusses the analysis of SuperGen application to a gasoline SUV in order to examine the BISG power and voltage mild hybrid functionality trade-off versus fuel consumption reduction on drive cycle. A significant engine down speeding was also applied based on the low speed torque enhancement afforded by SuperGen boosting capability, both transiently, and sustainably at steady state engine operation. This has been demonstrated and reported on the well-published Jaguar Land Rover (JLR) Ultraboost project. Finally, the part load “boost-ondemand” was used to evaluate advanced combustion modes not easily achievable with conventional turbocharger technology, namely; aggressive Miller cycle with early inlet valve closing; EGR diluted stoichiometric homogenous operation and un-throttled lean stratified combustion.
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