Numerical simulation on characteristics of knock combustion of small two-stroke direct injection engine

In order to understand the impact of ignition parameters on the knock of two-stroke kerosene aero-piston engine, the calculation model of the engine and the combustion chamber was established by using GT-Power and AVL Fire software. And the validity of the model was verified by the test data. The characteristics of average pressure and temperature, heat release rate, cumulative heat release rate and knock intensity distribution in the cylinder under 5 000 r/min and large load conditions were studied. The simulation and test results show that when angle of ignition advance changes from 15℃A to 35℃A, the torque, power, and average pressure, mean pressure and temperature, heat release rate and the accumulated heat release rate increase, accompanied by knock intensity tends to increase. When the asynchronous ignition phase changes from 0℃A to 5℃A, the torque and power shows slightly decreasing trend. Due to the turbulent kinetic energy near the spark plug increases, the flame propagation speed up, the reaction time at the end of the mixed gas becomes shorter, and the knock tendency of the two-stroke engine decreases.