Direct Injection Stratified Charge Engine by Impingement of Fuel Jet (OSKA)-Performance and Combustion Characteristics

1990 ◽  
Author(s):  
Satoshi Kato ◽  
Shigeru Onishi ◽  
Shinji Kobayashi
Author(s):  
T. Anand Kumar ◽  
J. M. Mallikarjuna ◽  
V. Ganesan

This paper describes a numerical study on fuel-air mixing and combustion in a direct injection stratified charge spark ignition engine. The in-cylinder flow, fuel-air mixing and combustion characteristics are investigated in a single cylinder, four-valve, four stoke, direct injection SI engine with pent-roof head and reverse tumble ports. The engine combustion chamber had the side mounted injector and spark plug at the center of pent-roof. Wall guided fuel-air mixing scheme has been adopted. The pre processor code Es-ice, used for dynamic grid generation preparation including description of piston and valve motion. Commercial computational fluid dynamics code Star-CD is used for solving governing equations and post processing of results. Combustion in the present study is simulated using Extended Coherent Flame Model-3z (ECFM-3Z). This model is based on a flame surface density transport equation that can describe inhomogeneous turbulent premixed combustion. In the present study, engine simulations has been carried out from 370 CAD before TDC and upto 90 CAD aTDC. The process includes the closing of the exhaust valves, the whole intake stroke, injection, combustion, and part of expansion. Three different injection timings are simulated viz. 55, 60 and 65 CAD bTDC. For validation of the code predicted results are compared with experimental results available in the literature. It is observed that, injection timing has an important role in mixture preparation and distribution around the spark plug. Hence, for the better combustion characteristics start of injection timing should be optimized.


2012 ◽  
Vol 614-615 ◽  
pp. 337-342
Author(s):  
Li Luo ◽  
Bin Xu ◽  
Zhi Hao Ma ◽  
Jian Wu ◽  
Ming Li

In this study, the effect of injection timing on combustion characteristics of a direct injection, electronically controlled, high pressure, common rail, turbocharged and intercooled engine fuelled with different pistacia chinensis bunge seed biodiesel/diesel blends has been experimentally investigated. The results indicated that brake specific fuel consumption reduces with the increasing of fuel injection advance angle and enhances with the increasing of biodiesel content in the blends. The peak of cylinder pressure and maximum combustion temperature increase evidently with the increment of fuel injection advance angle. However, the combustion of biodiesel blends starts earlier than diesel at the same fuel injection advance angle. At both conditions, the combustion duration and the peak of heat release rate are insensitive to the changing of injection timing.


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