Effect of Variable Valve Timing on Diesel Combustion Characteristics

2010 ◽  
Author(s):  
William De Ojeda
Keyword(s):  
Combustion Characteristics ◽  
Variable Valve Timing ◽  
Diesel Combustion ◽  
Valve Timing ◽  
Variable Valve

Achievement of Medium Speed and Load Premixed Diesel Combustion With Variable Valve Timing

2005 ◽  
Author(s):  
Yutaka Murata ◽  
Daisuke Kawano ◽  
Jin Kusaka ◽  
Yasuhiro Daisho ◽  
Hisakazu Suzuki ◽  
...  
Keyword(s):  
Variable Valve Timing ◽  
Diesel Combustion ◽  
Valve Timing ◽  
Medium Speed ◽  
Variable Valve

Achievement of Medium Engine Speed and Load Premixed Diesel Combustion with Variable Valve Timing

2006 ◽  
Author(s):  
Yutaka Murata ◽  
Jin Kusaka ◽  
Matsuo Odaka ◽  
Yasuhiro Daisho ◽  
Daisuke Kawano ◽  
...  
Keyword(s):  
Engine Speed ◽  
Variable Valve Timing ◽  
Diesel Combustion ◽  
Valve Timing ◽  
Variable Valve

3108 Control of Ignition Timing of Premixed Diesel Combustion with Variable Valve Timing

2005 ◽  
Vol 2005.3 (0) ◽  
pp. 55-56
Author(s):  
Yutaka MURATA ◽  
Daisuke KAWANO ◽  
Jin KUSAKA ◽  
Yasuhiro DAISHO ◽  
Hisakazu SUZUKI ◽  
...  
Keyword(s):  
Variable Valve Timing ◽  
Diesel Combustion ◽  
Valve Timing ◽  
Ignition Timing ◽  
Variable Valve

Emissions suppression mechanism of premixed diesel combustion with variable valve timing

2007 ◽  
Vol 8 (5) ◽  
pp. 415-428 ◽  
Author(s):  
Y Murata ◽  
J Kusaka ◽  
M Odaka ◽  
Y Daisho ◽  
D Kawano ◽  
...  
Keyword(s):  
Thermal Efficiency ◽  
Fuel Injection ◽  
Three Dimensional ◽  
Expansion Ratio ◽  
Variable Valve Timing ◽  
Diesel Combustion ◽  
Valve Timing ◽  
Detailed Chemistry ◽  
Suppression Mechanism ◽  
Variable Valve

A variable valve timing (VVT) mechanism is applied to achieve premixed diesel combustion at higher load for low emissions and high thermal efficiency in a light-duty diesel engine. By means of late intake valve closing (LIVC), compressed gas temperatures near the top dead centre are lowered, thereby preventing too early ignition and increasing ignition delay to enhance fuel-air mixing. The variability of an effective compression ratio has significant potential for ignition timing control of conventional diesel fuel mixtures. At the same time, the expansion ratio is kept constant to ensure thermal efficiency. Combining the control of LIVC, exhaust gas recirculation (EGR), supercharging systems, and high-pressure fuel injection equipment can simultaneously reduce NO x and smoke. The NO x and smoke suppression mechanism in the premixed diesel combustion is analysed using a three-dimensional computational fluid dynamics (3D-CFD) code combined with detailed chemistry. LIVC can achieve a significant NO x and smoke reduction due to lowering combustion temperatures and avoiding local overrich regions in the mixtures respectively.

A Multi-Cylinder HCCI Engine Model for Control

2004 ◽  
Author(s):  
Jason S. Souder ◽  
Parag Mehresh ◽  
J. Karl Hedrick ◽  
Robert W. Dibble
Keyword(s):  
Design Process ◽  
Control Design ◽  
The Other ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Coupling Effects ◽  
Hcci Engine ◽  
Engine Model ◽  
Hcci Engines ◽  
Variable Valve

Homogeneous charge compression ignition (HCCI) engines are a promising engine technology due to their low emissions and high efficiencies. Controlling the combustion timing is one of the significant challenges to practical HCCI engine implementations. In a spark-ignited engine, the combustion timing is controlled by the spark timing. In a Diesel engine, the timing of the direct fuel injection controls the combustion timing. HCCI engines lack such direct in-cylinder mechanisms. Many actuation methods for affecting the combustion timing have been proposed. These include intake air heating, variable valve timing, variable compression ratios, and exhaust throttling. On a multi-cylinder engine, the combustion timing may have to be adjusted on each cylinder independently. However, the cylinders are coupled through the intake and exhaust manifolds. For some of the proposed actuation methods, affecting the combustion timing on one cylinder influences the combustion timing of the other cylinders. In order to implement one of these actuation methods on a multi-cylinder engine, the engine controller must account for the cylinder-to-cylinder coupling effects. A multi-cylinder HCCI engine model for use in the control design process is presented. The model is comprehensive enough to capture the cylinder-to-cylinder coupling effects, yet simple enough for the rapid simulations required by the control design process. Although the model could be used for controller synthesis, the model is most useful as a starting point for generating a reduced-order model, or as a plant model for evaluating potential controllers. Specifically, the model includes the dynamics for affecting the combustion timing through exhaust throttling. The model is readily applicable to many of the other actuation methods, such as variable valve timing. Experimental results validating the model are also presented.

Application of Multi-Objective Genetic Algorithm (MOGA) for Design Optimization of Valve Timing at Various Engine Speeds

2011 ◽  
Vol 264-265 ◽  
pp. 1719-1724 ◽  
Author(s):  
A.K.M. Mohiuddin ◽  
Md. Ataur Rahman ◽  
Yap Haw Shin
Keyword(s):  
Genetic Algorithm ◽  
Design Optimization ◽  
Robust Design Optimization ◽  
Primary Concern ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Engine Valve ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm ◽  
Variable Valve

This paper aims to demonstrate the effectiveness of Multi-Objective Genetic Algorithm Optimization and its practical application on the automobile engine valve timing where the variation of performance parameters required for finest tuning to obtain the optimal engine performances. The primary concern is to acquire the clear picture of the implementation of Multi-Objective Genetic Algorithm and the essential of variable valve timing effects on the engine performances in various engine speeds. Majority of the research works in this project were in CAE software environment and method to implement optimization to 1D engine simulation. The paper conducts robust design optimization of CAMPRO 1.6L (S4PH) engine valve timing at various engine speeds using multiobjective genetic algorithm (MOGA) for the future variable valve timing (VVT) system research and development. This paper involves engine modelling in 1D software simulation environment, GT-Power. The GT-Power model is run simultaneously with mode Frontier to perform multiobjective optimization.

Development of a Hydraulic Variable Valve Timing Control System with an Optimum Angular Position Locking Mechanism

2012 ◽  
Author(s):  
Takahiro Miura ◽  
Shunichi Aoyama ◽  
Kaoru Onogawa ◽  
Takaya Fujia ◽  
Tetsuro Murata ◽  
...  
Keyword(s):  
Control System ◽  
Angular Position ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Timing Control ◽  
Locking Mechanism ◽  
Variable Valve
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