G070021 NO-Concentration Prediction of HCCI Combustion with Non-Uniformity of Mixture Temperature

Abstract

Temperature distribution of the mixture inside engine cylinder at intake-valve closing of a HCCI engine has been estimated, using the two pressure histories (cited from reference literature) of the same engine but with intentionally different intake temperatures. Our method of the estimation utilizes the two phenomena that are appreciably dependent on the mixture temperature, i.e., NO emission and autoignition-delay. Our analysis indicates that the temperature history of each local volume of the mixture asymptotically settles down to each certain history when the number of local volumes in our multi-zone model is increased, and that the number of local volumes necessary for the correct temperature estimation is about 15.