In order to solve a difficult problem of inlet that its compression doesnt well match with free Mach number within large Mach number range

an inlet with total mass capture was explored. Theory relations that should be met in inlet design process were obtained according to aerodynamics analysis. Based on these relations

an inlet example was designed and its variable geometry law was gotten. Numerical simulation was used to research the flowfiled and performance of the inlet

whose mass flow rate could be over 099 from Mach number 12 to 40. Preliminary results show that an inlet with total mass flow capture within wide Mach number can be designed by matching the free Mach number

contraction ratio and variable geometry law exactly

and cowl wall shape has characteristic of “S”.