Aspects of combustion process in a high pressure direct fuel injection two-stroke engine

The paper presents combustion process in loop scavenging two-stroke engine with high pressure direct injection of gasoline. A new method of determination of heat release rate on the base of experimental test in a two-stroke engine with direct gasoline injection is also presented. The target of the work was achieving of information about implementation of approximated Viebe function in mathematical models and simulation computer programs of a combustion process in spark ignition two-stroke engine with direct fuel injection due to the lack of such data in the literature. The paper show propagation of the flame in the combustion chamber depending on charge flow after scavenge process. The paper presents several examples of heat release and approximate function, for which variable coefficients of Viebe function were determined for certain rotational speeds at wide opening throttle. Pressure measurements were carried out on the engine Robin EC12 wit capacity 115 cm3. Determination of heat release and burned fuel rate was calculated by means of own computer program. The paper also presents the method of determination of variable specific heat coefficients in the function of crankshaft rotation, which are also used in modelling of the engine processes.