Abstract: The flowfields around a separating missile in supersonic free stream are studied numerically. Several typical flowfield structures in various separation distances are obtained. Two typical flow patterns are consistent very well with that observed in experiment. When the separation distance is small, the region between two stages is filled with "dead water" flow, the bottom drag of forebody is negative, the typical "afterbody effect" phenomenon occurs. When the separation distance is large, the complex interactive waves system is observed. After centain separation distance, the normal shock wave is formed in the front of the separated flow region before afterbody, hence the afterbody effect to forebody has been cut off.

Key words: separation between two stages, separated flow, numerical simulation