Experimental evaluation of local instantaneous heat transfer characteristics in the combustion chamber of air-cooled direct injection diesel engine

Capturing the physics related to the processes occurring in the two-phase flow of a direct-injection diesel engine requires a highly sophisticated modeling approach. The representative interactive flamelet (RIF) model has gained widespread attention owing to its ability of correctly describing ignition, combustion, and pollutant formation phenomena. This is achieved by incorporating very detailed chemistry for the gas phase as well as for the soot particle growth and oxidation, without imposing any significant computational penalty. This study addresses the part load soot underprediction of the model, which has been observed in previous investigations. By assigning flamelets, which are exposed to the walls of the combustion chamber, with heat losses calculated in a computational fluid dynamics (CFD) code, predictions of the soot emissions in a small-bore direct-injection diesel engine are substationally improved. It is concluded that the experimentally observed emissions of soot may have their origin in flame quenching at the relatively cold combustion chamber walls.

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Investigation of a direct injection diesel engine with a rapid stopping system. 2nd Report. Effects of combustion chamber shape and intake swirl on adhered fuel on a cold wall.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B ◽

10.1299/kikaib.54.3585 ◽

1988 ◽

Vol 54 (508) ◽

pp. 3585-3590

Author(s):

Hideyuki TSUNEMOTO ◽

Takanobu YAMADA ◽

Hiromi ISHITANI

Keyword(s):

Diesel Engine ◽

Combustion Chamber ◽

Direct Injection ◽

Cold Wall ◽

Direct Injection Diesel Engine ◽

Intake Swirl

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Experimental and Theoretical Optimization of Combustion Chamber and Fuel Distribution for the Low Emission Direct-Injection Diesel Engine

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.1501077 ◽

2002 ◽

Vol 125 (1) ◽

pp. 351-357 ◽

Cited By ~ 13

Author(s):

Y. Kidoguchi ◽

M. Sanda ◽

K. Miwa

Keyword(s):

Diesel Engine ◽

Combustion Chamber ◽

Direct Injection ◽

Combustion Process ◽

Mixture Distribution ◽

Initial Mixture ◽

Injection Timing ◽

Particulate Emissions ◽

Particulate Emission ◽

Direct Injection Diesel Engine

Effects of combustion chamber geometry and initial mixture distribution on the combustion process were investigated in a direct-injection diesel engine. In the engine experiment, a high squish combustion chamber with a squish lip could reduce both NOx and particulate emissions with retarded injection timing. According to the results of CFD computation and phenomenological modeling, the high squish combustion chamber with a central pip is effective to keep the combusting mixture under the squish lip until the end of combustion and the combustion region forms rich and highly turbulent atmosphere. This kind of mixture distribution tends to reduce initial burning, resulting in restraint of NOx emission while keeping low particulate emission.

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