Novel Method of Setting Initial Conditions for Multi-Zone HCCI Combustion Modeling 2007-01-0674

Combustion in Homogeneous Charge Compression Ignition (HCCI) engines is the subject of intensive combustion modeling efforts because, while they have potential for low fuel consumption and emissions, they also suffer from problems of combustion control. Modeling studies are being used to predict the effects of changing controllable parameters and to ‘measure’ important combustion-related phenomena which can not be observed directly. A significant limitation of most current combustion models is that they still rely on arbitrarily adjusting initial conditions, (especially temperature) in order to match experimental results. This limits the confidence with which models can be used to predict HCCI combustion behavior over any range of conditions wider than available experimental data.

This paper describes a new method to solve the initial condition problems for HCCI combustion modeling based on simulated heat transfer between intake and residual components. The capability of the modified model is demonstrated over a wide range of experimental data and shows that the modified multi-zone combustion model can accurately set initial conditions and thus predict the combustion behaviour without arbitrarily adjusting initial temperature.