A kind of three-dimensional flow-path of the ram-rotor was designed in this paper according to the design method of the typical supersonic intake of aircraft and missiles

especially the design method of the compression ramp

the throat and the subsonic diffuser.The design Mach number of the flow-path was based on the averaged relative Mach number

regardless of the change of incoming Mach number along radial direction of the flow-path.Then

the flowfield of the designed flow-path was simulated numerically with computational fluid dynamics software at design point.The purpose of simulation was to obtain the details of the flowfield

including the structure of the shock wave system

position of flow separation zone

and so on.The performance of the ram-rotor was also evaluated.The numerical results show the structure of the shock wave system in the flow-path is similar to that in the supersonic intake.To improve the overall performance of the ram-rotor

the reasonable compromise between the total pressure ratio and the isentropic adiabatic efficiency should be reached.The structure optimization of the flow-path and the configuration of the shock wave system have great influence on the performance of the ram-rotor.