THE HEAT TRANSFER COEFFICIENT CALCULATION IN THE ICE CYLINDER BASED ON IN-CYLINDER PRESSURE DATA

Abstract

In this paper the calculations algorithm of heat-transfer coefficient in the combustion chamber of the internal combustion engine is presented. Developed algorithm is based on the in cylinder pressure data. The proposed algorithm can be helpful to determine the average values of heat-transfer coefficient from working medium to the combustion chamber walls (crown of a cylinder head, cylinder walls and piston head) during combustion process. The calculation method includes modified one zone heat release model in combustion chamber of SI engine. Proposed method consists in closing the energy balance equation by the coefficient which expresses the heat losses to the walls of the combustion chamber. The average value of the heat losses during combustion process is calculated by two steps. Firstly, the integration of the energy balance equation (without specifying the heat losses) leads to designation of the so-called net value of heat released in cylinder. In the next step the amount of the total energy supplied to the cylinder is determined taking into account the chemical energy of the supplied fuel. The difference between the supplied value of chemical energy and heat released net value allows to determine the heat losses average value. In last stage, the heat flow equation leads to calculate the mean value of heat transfer coefficient during combustion process.