Study of Improvement for Combustion Stability under Cold Start Condition of DI Diesel Engine (Second Report)

-Application of TI(Time-scale Interaction) Combustion Model for Cold Start Condition-

Abstract

Diesel engines of low compression ratio have issues of white smoke and combustion instability under cold start conditions. TI(Time-scale Interaction) combustion model applied cold start conditions in order to resolve those issues. TI combustion model has been developed for simulating combustion phenomena with high accuracy from premixed charged combustion to diffusion combustion. This model is based on a reasonable combustion mode, taking into account the characteristic time scale of chemical reactions and turbulence eddy break-up. In addition, parameters of the ignition model and computational grids near glow-plug were improved to apply under cold start conditions. Comparisons of measured and calculated heat release patterns show good agreement under cold conditions. It was shown by application of TI combustion model under cold start conditions that the fuel reaction near the glow plug is significant for ignition.