A Prediction Method for Aerodynamic Characterization of Grid -Fin Configurations at Supersonic Speeds

** † A rapid prediction method has been developed for the estimation of aerodynamic characteristics of grid fin configurations at supersonic Mach numbers. The method is based on shock -expansion theory. The shock and expansion relations and the interactions between the shock and expansion waves are used to predict the pressure distribution inside each grid fin cell. Effect of body is modeled using doublet in the cross flow plane. The effect of symmetric separated vortices from the leeward side of body is also modeled using empirical data for the strength and location of vortices. The present method has been validated with available experimental data for bodies with grid fins. The comparison of normal force coefficient on the individual grid fins as well as the overall normal force, pitc hing moment and axial force coefficient with experimental data is good.