Aeropredictive methods for missile analysis

Abstract

Various computational methods and operational computer codes used to predict and evaluate aerodynamic coefficients and flight performance of missile bodies are reviewed. Aerodynamic effects of symmetric and asymmetric flow separation are discussed, as are the differences inherent in estimating the properties of the resulting flowfields. The semi-empirical aeroprediction codes NSWC and MISSILED DATCOM are compared against experimental data for a variety of configuration geometries and flight conditions; the MISSLE DATCOM code is further used for a comparison with wind tunnel data for a Standard-type missile model. The NSWC and MISSILE DATCOM code are found to provide accurate prediction of normal force coefficients at both low and high angle of attack, although the nonlinear effects of separated flow are only partially captured. Center of pressure coefficients are generally unpredicted, but of the correct order of magnitude. The accuracy of drag coefficient prediction is seen to diminish as missile configuration geometry becomes more complex. The NSWC program provides satisfactory prediction of pitch damping coefficients, while the MISSILE DATCOM output is inconclusive. The NSWC and MISSILE DATCOM aeroprediction code are considered suitable for preliminary design and aerodynamic analysis.