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Experimental Investigations on the Influence of Valve Timing and Multi-Pulse Injection on GCAI Combustion

Indian Institute of Technology Madras-Jensen Samuel, Santhosh Mithun, Kasinath Panda, A Ramesh
MSCE, RWTH Aachen University-Maximilian Wick, Jakob Andert
Published 2019-04-02 by SAE International in United States
Gasoline Controlled Auto-Ignition (GCAI) combustion, which can be categorized under Homogeneous Charge Compression Ignition (HCCI), is a low-temperature combustion process with promising benefits such as ultra-low cylinder-out NOx emissions and reduced brake-specific fuel consumption, which are the critical parameters in any modern engine. Since this technology is based on uncontrolled auto-ignition of a premixed charge, it is very sensitive to any change in boundary conditions during engine operation. Adopting real time valve timing and fuel-injection strategies can enable improved control over GCAI combustion. This work discusses the outcome of collaborative experimental research by the partnering institutes in this direction. Experiments were performed in a single cylinder GCAI engine with variable valve timing and Gasoline Direct Injection (GDI) at constant indicated mean effective pressure (IMEP). In the first phase intake and exhaust valve timing sweeps were investigated. It was found that the Intake Valve Closing (IVC) timing and Exhaust Valve Closing (EVC) timing have a dominant influence on combustion, performance and emission parameters.In the second phase of experiments, multiple injection strategies were investigated. Here the influences…
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Valve Opening and Closing Event Finalization for Cost Effective Valve Train of Gasoline Engine

Maruti Suzuki India, Ltd.-Sanjay Poonia, Amandeep Singh, Narinder Kumar, Jaspreet Singh, Shailender Sharma
Published 2019-04-02 by SAE International in United States
With more stringent emission norm coming in future, add more pressure on IC engine to improve fuel efficiency for survival in next few decades. In gasoline SI (spark ignition) engine, valve events have major influence on fuel economy, performance and exhaust emissions. Optimization of valve event demands for extensive simulation and testing to achieve balance between conflicting requirement of low end torque, maximum power output, part load fuel consumption and emission performance. Balance between these requirements will become more critical when designing low cost valve train without VVT (Variable valve timing) to reduce overall cost of engine.Higher CR (Compression ratio) is an important low cost measure to achieve higher thermal efficiency but creates issue of knocking thereby limiting low speed high load performance. The effective CR reduction by means of late intake valve closing (LIVC) is one way to achieve higher expansion ratio while keeping high geometric CR. Due to backflow at low engine speed by late IVC (Intake valve closing) it is challenging to implement late IVC without compromising low end high load performance…
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Application of Advanced Modelling Techniques in the Development of a High Specific Output 3 Cylinder Gasoline Engine

Mahle Powertrain Ltd.-James Miller, Matthew Grove, Dominic Baker, James Taylor, David Pates
Published 2019-04-02 by SAE International in United States
The challenges of ever increasing combustion engine complexity coupled with the introduction of new and ever more stringent emissions regulations place a unique strain on the time available during the base engine hardware development and calibration phase of the product development cycle. Considering state of the art gasoline engine architecture (dual variable valve timing, direct injection with turbocharger) it is common to have at least 12 degrees of freedom as system inputs. The understanding of interactions and inter-dependencies of these inputs is therefore key in optimising the performance of the engine.MAHLE Powertrain has developed a process using a global Design of Experiment (DoE) technique based on Gaussian processes that can be used to accurately model and optimise many aspects of an engine’s performance. The output of this optimisation is then coupled with the proposed calibration architecture, which enables key calibration models to be completed early in the product development program.In this paper careful application of this methodology has been applied to a high specific output, 3 cylinder gasoline internal combustion engine which has allowed for…
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Effects of Bore-to-Stroke Ratio on the Efficiency and Knock Characteristics in a Single-Cylinder GDI Engine

Hyundai Motor Company-Byeongseok Lee, Dongwon Jung, Soo Hyung Woo
Seoul National University-Seokwon Cho, Sechul Oh, Chiheon Song, Woojae Shin, Sejin Song, Han Ho Song, Kyoungdoug Min
Published 2019-04-02 by SAE International in United States
As a result of stringent global regulations on fuel economy and CO2 emissions, the development of high-efficiency SI engines is more urgent now than ever before. Along with advanced techniques in friction reduction, many researchers endeavor to decrease the B/S (bore-to-stroke) ratio from 1.0 (square) to a certain value, which is expected to reduce the heat loss and enhance the burning rate of SI engines. In this study, the effects of B/S ratios were investigated in aspects of efficiency and knock characteristics using a single-cylinder LIVC (late intake valve closing) GDI (gasoline direct injection) engine. Three B/S ratios (0.68, 0.83 and 1.00) were tested under the same mechanical compression ratio of 12:1 and the same displacement volume of 0.5 L. The head tumble ratio was maintained at the same level to solely investigate the effects of geometrical changes caused by variations in the B/S ratio. In addition, because the engine was equipped with a dual CVVT (continuous variable valve timing) system, the valve timings were optimized to fully exploit the potential of each geometry. As…
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The Application of Controlled Auto-Ignition Gasoline Engines -The Challenges and Solutions

Brunel University-Hua Zhao
China North Engine Research Institute-Yan Zhang, Yufeng Li, Honglin Bai
Published 2019-04-02 by SAE International in United States
Controlled Auto-Ignition (CAI) combustion, also known as Homogeneous Charge Compression Ignition (HCCI), has the potential to simultaneously reduce the fuel consumption and nitrogen oxides emissions of gasoline engines. However, narrow operating region in loads and speeds is one of the challenges for the commercial application of CAI combustion to gasoline engines. Therefore, the extension of loads and speeds is an important prerequisite for the commercial application of CAI combustion. The effect of intake charge boosting, charge stratification and spark-assisted ignition on the operating range in CAI mode was reviewed. Stratified flame ignited (SFI) hybrid combustion is one form to achieve CAI combustion under the conditions of highly diluted mixture caused by the flame in the stratified mixture with the help of spark plug. CAI combustion in two-stroke gasoline engine can be used to enhance the torque of a four-stroke gasoline engine with the same displacement at the same indicated mean effective pressure. Poppet-valved two-stroke gasoline engines with normal valve lift and variable valve timing device, and uniflow two-stroke engine with gas exchange process completed by…
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Analysis of a New VVT Trapezoidal Rotary Valve

Universidade do Minho-Jorge Martins, Afonso Baptista, Rui Pinto, F. P. Brito, Tiago J. Costa
Published 2019-04-02 by SAE International in United States
The current study introduces a Variable Valve Timing (VVT) trapezoidal rotary valve for a 4-stroke spark-ignition engine. Being trapezoidal, enables the rotary valve to change the inlet and exhaust timing continuously, therefore allowing it to control the engine load without the need for a throttle valve. The geometry of the valve is studied in detail, calculating the intersection areas between the windows (ports) of the valve and those of the combustion chamber during the engine cycle. As the valve openings are trapezoidal and the opening of the combustion chamber is trapezoidal as well, there is a multitude of geometry variables that need to be optimized. During idle the engine needs to breathe through just a very small area, while during high load operation the opening needs to be generous. Finally, the trapezoidal rotary valve system is compared to a conventional VVT system.
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Application of Multi-Objective Optimization Techniques for Improved Emissions and Fuel Economy over Transient Manoeuvres

Ford Motor Co Ltd-Mark Cary, Robert Lygoe
Loughborough University-Samuel David Le Corre, Byron Mason, Thomas Steffen, Edward Winward, Zhijia Yang, Thomas Childs
Published 2019-04-02 by SAE International in United States
This paper presents a novel approach to augment existing engine calibrations to deliver improved engine performance during a transient, through the application of multi-objective optimization techniques to the calibration of the Variable Valve Timing (VVT) system of a 1.0 litre gasoline engine. Current mature calibration approaches for the VVT system are predominantly based on steady state techniques which fail to consider the engine dynamic behaviour in real world driving, which is heavily transient.In this study the total integrated fuel consumption and engine-out NOx emissions over a 2-minute segment of the transient Worldwide Light-duty Test Cycle are minimised in a constrained multi-objective optimisation framework to achieve an updated calibration for the VVT control. The cycle segment was identified as an area with high NOx emissions. The optimisation framework was developed around a Mean Value Engine Model (MVEM) with representative engine controls which was validated against an engine tested on a dynamometer. The aim of this study was to demonstrate a practical benefit without having to significantly change the existing engine control strategy. Offline optimization with the…
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Application Layer - Diagnostics

Truck Bus Control and Communications Network Committee
  • Ground Vehicle Standard
  • J1939/73_201901
  • Current
Published 2019-01-31 by SAE International in United States
SAE J1939-73 Diagnostics Application Layer defines the SAE J1939 messages to accomplish diagnostic services and identifies the diagnostic connector to be used for the vehicle service tool interface. Diagnostic messages (DMs) provide the utility needed when the vehicle is being repaired. Diagnostic messages are also used during vehicle operation by the networked electronic control modules to allow them to report diagnostic information and self-compensate as appropriate, based on information received. Diagnostic messages include services such as periodically broadcasting active diagnostic trouble codes, identifying operator diagnostic lamp status, reading or clearing diagnostic trouble codes, reading or writing control module memory, providing a security function, stopping/starting message broadcasts, reporting diagnostic readiness, monitoring engine parametric data, etc. California-, EPA-, or EU-regulated OBD requirements are satisfied with a subset of the specified connector and the defined messages.
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Optimized Exhaust After-Treatment System Solution for Indian Heavy Duty City Bus Application - The Challenges Involved and the Right Approach to Meet Future BS VI Emission Legislations and Real World Driving Emissions

FEV Europe GmbH-Markus Ehrly
FEV India Pvt, Ltd.-Ashraf Emran, Rouble Sandhu, Rajesh Santhoji Kale, Vijay Sharma, Devising Rathod
Published 2019-01-09 by SAE International in United States
The vehicular pollution and emission levels are alarmingly increasing in India. The metro and urban cities are worst hit by the gaseous and particulate emissions produced by internal combustion engine powered vehicles. Following the trend from other developed countries, Government of India (GOI) has decided to migrate from existing BS IV legislation directly to BS VI legislation from April 2020 all across India. This migration in emission legislation took almost 10 years to be implemented in European Union (EU) countries. However, for India, the targeted implementation time is just 3 years, making it an uphill challenge for all the vehicle manufacturers. City bus is one such applications, which run mostly within the city and currently are powered by conventional Diesel engines. The vehicle manufacturers should focus on finding an optimized solution for meeting the future emission legislation in true sense. This calls for meeting the emission limits with not only the legislative engine dynamometer cycles but also considering the real world driving cycle (RDE) in their solution.The study presented here involves finding the optimized solution…
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The Fuel Economy Improvement through the Knock Margin Expansion in a Turbocharged Gasoline Direct Injection Engine

Korea Advanced Inst. of Science & Tech.-Ji Yong Shin, Chansoo Park, Jinyoung Jung, Choongsik Bae
Published 2018-09-10 by SAE International in United States
Knocking combustion limits the downsized gasoline engines’ potential for improvement with regard to fuel economy. The high in-cylinder pressure and temperature caused by the adaptation of a turbocharger aggravates the tendency of the end-gas to autoignite. Thus, the knocking combustion does not allow for further advancing of the combustion phase. In this research, the effects of the ignition and valve timings on knocking combustion were investigated under steady-state conditions. Moreover, the optimal ignition and valve timings for the transient operations were derived with the aim of a greater fuel economy improvement, based on the steady-state analysis. A 2.0 liter turbocharged gasoline direct injection engine with continuously variable valve timing (CVVT), was utilized for this experiment. 2, 10, and 18 bar brake mean effective pressure (BMEP) load conditions were used to represent the low, medium, and high load operations, respectively. The engine speed was set at 1,500 RPM since the low speed conditions were more vulnerable to knocking combustion than the high speed conditions. Both the intake and the exhaust valve timings were controlled from the…
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