Strength analysis and structural optimization of detonation combustor to multi-cycle pulse detonation loading

The equivalent stress of the detonation combustor was computed and researched using the axisymmetric finite element modal and whole cycle pressure obtained by numerical simulation.The effect of the temperature was calculated using the measured thermal equilibrium temperature data,and the primary optimization of the thickness was completed for given fatigue life.It is found that the equivalent stress of the detonation combustor to multi-cycle detonation loading is a little bigger than that to single cycle detonation loading,and the difference of the same position is less than 4%.The equivalent stress of the detonation combustor at the same position is periodic when the PDE(pulse detonation engine) works circularly,and the maximal equivalent stress in every cycle is nearly equal.The maximal equivalent stress has an increscent trend along with the spread of detonation wave.The maximal equivalent stress at the same position is nearly equal when the frequency changes among 10~50Hz.The equivalent stress with temperature is nearly equal to that without temperature when it is assumed that the detonation combustor has the same temperature in the radial direction and can expand freely in the axial direction,but the equivalent strain increases.