Numerical Study of Effects of Fuel Injection Timings on CAI/HCCI Combustion in a Four-Stroke GDI Engine

2005 ◽  
Author(s):  
Li Cao ◽  
Hua Zhao ◽  
Xi Jiang ◽  
Navin Kalian
Keyword(s):  
Fuel Injection ◽  
Numerical Study ◽  
Hcci Combustion ◽  
Gdi Engine

scholarly journals Numerical study of flame structure in the mild combustion regime

2015 ◽  
Vol 19 (1) ◽  
pp. 21-34 ◽  
Author(s):  
Amir Mardani ◽  
Sadegh Tabejamaat
Keyword(s):  
Fuel Injection ◽  
Numerical Study ◽  
Flame Structure ◽  
Combustion Regime ◽  
Low Oxygen ◽  
Mixing Rate ◽  
Jet Flame ◽  
Reduced Mechanism ◽  
Mild Combustion ◽  
O2 Concentration

In this paper, turbulent non-premixed CH4+H2 jet flame issuing into a hot and diluted co-flow air is studied numerically. This flame is under condition of the moderate or intense low-oxygen dilution (MILD) combustion regime and related to published experimental data. The modelling is carried out using the EDC model to describe turbulence-chemistry interaction. The DRM-22 reduced mechanism and the GRI2.11 full mechanism are used to represent the chemical reactions of H2/methane jet flame. The flame structure for various O2 levels and jet Reynolds numbers are investigated. The results show that the flame entrainment increases by a decrease in O2 concentration at air side or jet Reynolds number. Local extinction is seen in the upstream and close to the fuel injection nozzle at the shear layer. It leads to the higher flame entertainment in MILD regime. The turbulence kinetic energy decay at centre line of jet decreases by an increase in O2 concentration at hot Co-flow. Also, increase in jet Reynolds or O2 level increases the mixing rate and rate of reactions.

Numerical study of the effect of piston top contour on GDI engine performance under catalyst heating mode

Fuel ◽  
2015 ◽  
Vol 157 ◽  
pp. 64-72 ◽  
Author(s):  
Zhaolei Zheng ◽  
Chuntao Liu ◽  
Xuefeng Tian ◽  
Xiaoyu Zhang
Keyword(s):  
Numerical Study ◽  
Engine Performance ◽  
Gdi Engine ◽  
Heating Mode

scholarly journals An Experimental and Modeling Study of HCCI Combustion Using n-Heptane

2009 ◽  
Vol 132 (2) ◽  
Author(s):  
Hongsheng Guo ◽  
W. Stuart Neill ◽  
Wally Chippior ◽  
Hailin Li ◽  
Joshua D. Taylor
Keyword(s):  
Low Temperature ◽  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Combustion Process ◽  
Injection System ◽  
Intake Manifold ◽  
Strong Impact ◽  
Oxides Of Nitrogen ◽  
Hcci Combustion ◽  
Modeling Study

Homogeneous charge compression ignition (HCCI) is an advanced low-temperature combustion technology being considered for internal combustion engines due to its potential for high fuel conversion efficiency and extremely low emissions of particulate matter and oxides of nitrogen (NOx). In its simplest form, HCCI combustion involves the auto-ignition of a homogeneous mixture of fuel, air, and diluents at low to moderate temperatures and high pressure. Previous research has indicated that fuel chemistry has a strong impact on HCCI combustion. This paper reports the preliminary results of an experimental and modeling study of HCCI combustion using n-heptane, a volatile hydrocarbon with well known fuel chemistry. A Co-operative Fuel Research (CFR) engine was modified by the addition of a port fuel injection system to produce a homogeneous fuel-air mixture in the intake manifold, which contributed to a stable and repeatable HCCI combustion process. Detailed experiments were performed to explore the effects of critical engine parameters such as intake temperature, compression ratio, air/fuel ratio, engine speed, turbocharging, and intake mixture throttling on HCCI combustion. The influence of these parameters on the phasing of the low-temperature reaction, main combustion stage, and negative temperature coefficient delay period are presented and discussed. A single-zone numerical simulation with detailed fuel chemistry was developed and validated. The simulations show good agreement with the experimental data and capture important combustion phase trends as engine parameters are varied.

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