Influence of axial length on rotating detonation engine

Based on 9 species and 19-step reaction,without consideration of the effect of viscosity,heat transmission and diffusion on flow,mixtures of hydrogen and oxygen were used to simulate rotating detonation engine flow field to research the effect of axial length on engine performance.Research show that:within a certain range,axial length has little influence on specific impulse of engine,but if axial length is too long,it will decrease specific impulse of engine;axial length has great influence on detonation pressure and temperature;if axial length is too little,the pressure of detonation wave is not high;if axial length is too long,the oblique detonation may decay;with the increase of axial length,the pressure of outlet continues to decrease owing to expansion;when axial length is 200mm,the average speed and specific impulse of engine reach the maximum value;azimuthal velocity decreases obviously cuttingdown the harmful influence on engine;the maximum thrust density decreases gradually;density difference in before and after shock wave decreases gradually,so that the thrust eccentricity could continue to decrease,thus effectively reducing angle scatter harmful influence.