Resistance is The article presents the results of the research of a charge swirl motion influence on working process, engine parameters and NOx emissions of a spark ignition premixed natural gas engine. The charge swirl motion was organized by tangential inflow channel. The engine work process research was performed using numerical modeling of physical and chemical processes in combustion chamber. The turbulent flow in combustion chamber, spark ignition and combustion of gas fuel were simulated. The simulation shows that a tangential channel allowed organizing a swirl motion of charge and increasing turbulent kinetic energy of flow in the combustion chamber. Swirl motion greatly affects the combustion process. The increase in the turbulent kinetic energy to the spark timing made it possible to substantially reduce the combustion time of the fuel. Replacement of one original channel by a tangential channel allowed reducing emissions of nitrogen oxides NOx. Physical and chemical processes in combustion chamber were simulated in Ansys Forte.

The paper introduces the results of studying the influence of intake ports shape on turbulization and charge swirl in the combustion chamber, combustion rate, ecological and indicator values of the engine. The study was carried out using mathematical simulation of physicochemical processes occurring in the combustion chamber of a piston engine during gas fuel combustion. The turbulent flow of the mixture, spark ignition and combustion of gas fuel are simulated. To simulate the turbulent flow, the RNG (k--ε)-model was used, to simulate the combustion of natural gas in the combustion chamber a model based on the specific surface area of the flame, the so-called G-equation model, was used. When simulating spark ignition, the model of discrete particles of the ignition kernel DPIK (Discrete Particle Ignition Kernel) was applied. As a result of simulation, we found that replacing one inlet channel with a tangential channel allows creating a vortex motion and increasing the turbulence of the mixture in the combustion chamber. An increase in the kinetic energy of the mixture before the spark is applied leads to a decrease in the combustion time. The use of swirling the charge on inlet by replacing one filling channel with a tangential one can significantly improve the environmental performance of the engine while maintaining fuel and economic indicators. The ANSYS Forte program was used to simulate the physicochemical processes in the combustion chamber

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