Viscous CFD calculations of grid fin missile aerodynamics in the supersonic flow regime

Abstract

Abstract : This report presents the results of an investigation to use viscous computational fluid dynamic calculations to predict the flowfleld and aerodynamic coefficients for a missile with grid fins in the supersonic flow regime. The calculations were made at Mach 2 and 3 and several angles of attack. The results were validated by compamig the computed aerodynamic coefficients against wind tunnel experimental data. Good agreement was found between the computed and experimental axial force coefficients, with the difference between 4 and 8%. Reasonable agreement was found for the normal force coefficient, with a difference of 8-16%. The agreement between the computed and experimental pitching moment coefficient was not as good, with a difference of 16-27%. Good agreement was found for the location of the center of pressure, with a difference of 6-10%. The flowlield around the individual grid fins and the normal force on the fins showed characteristics similar to those found in an earlier study.