Effect of freestream-jet plume interaction on aerodynamic coefficients with different flared aft-bodies

Abstract

Experiments were carried out on a blunt-cone-cylinder geometry with various flared aft body configurations to understand the effect freestream (M=5)-jet plume (M=2.65) interaction on aerodynamic coefficients. Supersonic jet plume of varying pressure ratios (Pj/P∞=0–130) were simulated and the model angle of attack (α) is varied from 0 to 4°. The complex freestream-jet plume interaction was captured through Schlieren flow visualization while the forces and moments are measured through conventional strain gauge balance. The introduction of supersonic jet plume resulted in reduction of aerodynamic coefficients in all the cases. The change in aerodynamic coefficients depends primarily on the extent of Plume Induced Flow Separation (PIFS) due to freestream-jet plume interaction and the aft body configurations. A reduction of 37–46% in axial force coefficient (CA), 20–23% in normal force coefficient (CN) and 31–72% in pitching moment coefficient (Cm) were observed due to freestream-jet plume interaction. In cylindrical aft body, separation due to freestream-jet plume interaction was found to be dominant whereas it is less pronounced in flared aft body configurations. Among the tested configurations 14and16° flared aft body configurations show more stability compared to cylindrical and other flared aft body configurations under jet plume-on and off conditions.