Numerical simulation of impact of ejection seat rocket motor ignition shock waves on aircraft windshield loading

Aircraft windshield fragmentation during seat ejection can adversely affect crew ejection from the aircraft safety. In this paper, the shock wave loads caused by the firing of an ejection seat rocket motor were simulated numerically, and the numerical simulation flow was designed with the dynamic grid technique. The results show that the pressure peak of the inner surface monitoring point at the front end of the windshield is 9.4% lower compared with the test value at the same location when the rocket engine is firing at 0 km/h velocity ejection, which proves the numerical simulation method feasible. The effects of rocket pack ignition shock waves on the aircraft windshield can be divided into shock wave loading phase and quasistatic pressure loading phase. The former has a large peak load and a short duration, while the latter has a small peak load and a long duration.At corners within the cockpit, converging phenomena occur during shock wave propagation, and the area near the cabin inner wall at the front and sides of the aircraft's windshield is more heavily loaded and has a higher risk of damage than other areas. The moment of maximum windshield loading for each calculated state is the moment of the first load peak. Due to the high velocity airflow blowing effect, the maximum windshield loading at 1100 km/h ejects is close to the zero velocity ejection value, acting in the opposite direction. The zero velocity ejection and impact loads at 1100 km/h eject should be emphasized in the windshield strength analysis.