Research on aerodynamic drag optimization design of base cavity for slender body

Focus on the aerodynamic drag reducing of slender body with the base cavity, configuration of the cavity is optimized by numerical method. There has been extensive investigation on the aerodynamic characteristics of cylindrical base cavity structures, but there is little research on base cavity with non-cylindrical configurations. Three kinds of base cavity which is different with tradition one, simple truncated-cone, half truncated-cone and half column, are investigated in the paper. Flow field parameters and of air drag coefficients for the three cases and the traditional cylindrical cavity were obtained by an axisymmetric Navier-Stokes equations. The calculation result shows that, the truncated-cone and column combined and the column is close to the base wall has the best aerodynamic drag reducing effect among the four cases calculated in this paper. Compared with traditional cylindrical structures, introducing a "cone" structure into the base cavity configuration is beneficial for reducing the aerodynamic resistance on a slender body. For the cavity configuration which mixed with cones and columns, their relative positions are crucial.