Abstract: The flow fields of a ventral diverterless high offset S-shaped inlet at Mach numbers from 0.85 to 1.50 are simulated using a numerical approach which has been validated by experimental data. Results indicate: (1) Most of the boundary layer of forebody is pushed away from the inlet by the design of the inlet aperture; (2) The pressure distributions of the bump surface at high subsonic speed and sonic speed are similar, but at low supersonic speed, the pressure distribution of the Bump surface is different from the previous two because of its different mechanism; (3) The counterrotating vortices at the lower part of the inlet exit are developed from the counterrotating vortices formed at the second turn of the S-shaped duct.

Key words: aerospace propulsion system, diverterless inlet, high offset, transonic inlet, S-shaped inlet, secondary flow