HC2-1: Potential of Thermal and Mixing Stratification for Reducing Pressure-rise rates in HCCI Engines(HC: HCCI Combustion,General Session Papers)

Abstract

The purpose of this study is to investigate the potential use ofin-eylinder therTnal and mixing stratification for reducing the pressure-rise rates in HCCI engines by going through numerical analysis with multi-zones modeling.The' computations are conducted using both a standard single-zone and the custom multi-zone version of the Senkin application ofthe CHEMKIN II kinetics rate code, and kinetie mechanisms for Di-Methyl Ether (DME). The objective ofcalculation with the multi-zones model is to examine the mechanism of therrnal and mixing stratified charge to reduce an excessive pressure-rise rates. The mechanism ofreducing the pressure-rise rates in the thermal and mixing stratified chargeis proved with 2-zones and 5-zenes model. It is found that thermal and mixing stratification have the effect ofreducing the pressure-rise rates (extended combustion duration) and have potential for extending the upper load limit in HCCI engines.

Advances in Theory and Technology Research of Low Temperature Combustion (LTC) for Diesel Engines

“…When the in-cylinder temperature is lower than 1650 K, no matter how the Φ and T in the cylinder change and develop, the combustion process can avoid the area that satisfies the generation conditions of NOx and soot emission, and ultralow NOx and soot emission can be realized simultaneously . Common LTCs include homogeneous charge compression ignition [9] (HCCI), premixed charge compression ignition [10] (PCCI), and reactivity controlled compression ignition [11] (RCCI). These techniques are the same in terms of fundamentals, but differ in approach.…”