In order to study start/unstart flow characteristic in the acceleration/deceleration process

an investigation of two-dimensional mixed-compression supersonic inlet was performed in steady/unsteady numerical simulation. The effect of absolute value of acceleration on inlet performance was analyzed at Mach number from 1.75 to 2.05 and four different absolute values of acceleration were considered. The results of steady and unsteady numerical simulations were compared. The results indicate: in both start and unstart processes

the flow characteristic of the unsteady case lags behind compared with the steady one's

and the larger absolute value of acceleration means more obvious phenomena. The performance in unsteady simulation obviously lags behind that in steady simulation. The start process of inlet spends more time than unstart process under the same absolute value of acceleration.