ОСОБЛИВОСТІ МОДЕЛЮВАННЯ ПРОЦЕСУ ЗГОРЯННЯ СИНТЕЗ-ГАЗУ В ПОРШНЕВИХ ДВИГУНАХ

The purpose of the work is to analyze the features of the working process in internal combustion engines when using synthetic gas with significant hydrogen content. At present, the effective use of synthetic gas allows you to use the energy resources of alcohol fuels and significantly increase the environmental performance of engines. In addition, the production of synthetic gas on board a vehicle in a certain way allows you to increase the fuel efficiency of the engine by using the energy of exhaust gases. The article considers the features of the combustion process of synthesis gas in the working cylinder of an internal combustion engine with spark ignition. The purpose of the study is also to estimate the parameters of heat release of synthesis gas. The most significant result is to obtain dependencies for determining the current values of the combustion character indicator m and the combustion duration φz in the heat release in professor's I. I. Wiebe model for spark-ignition engines operating on synthesis gas with a range of changes in the excess air coefficient α (1.0...2.2) and a variation in the hydrogen content in the fuel composition of 30...100% by volume. The variability of the combustion index m (1.6...5.5) in the semi-empirical heat release in professor's  I. I. Wiebe model has been established, which largely corresponds to the real law of heat release in experimental studies. The proposed dependencies for determining m and φz allow us to take into account the peculiarities of the combustion process of synthesis gas in spark-ignition engines and thereby significantly increase the accuracy of determining the indicator pressure in the working cylinder (the relative root-mean-square error does not exceed 4.5%). The conducted studies and mathematical modeling of various engine sizes allowed us to establish a possible range of changes in the combustion character index m in professor's  I. I. Wiebe model, which is 1.6…5.5. The obtained research results can be used in the design and construction of new spark-ignition engines operating on alternative fuels, or the conversion of existing ones, as well as to refine the mathematical model of the combustion process.