Improved Method for Predicting Axial Force at High Angle of Attack

摘要

An improved semiempirical method for axial force calculation on missileconfigurations has been developed. The method uses the theoretical methods currently used in the Naval Surface Warfare Center Aeroprediction Code for zero angle-of-attack (AOA) axial force computations and several wind tunnel data bases to compute changes in axial force at AOA. The method is applicable to bodies alone, wing-body, and wing-body-tail configurations for both zero and non-zero control deflections. It has been developed to allow computation for AOA to 90 deg at any Mach number. However, it has been validated against data only to Mach number of 4.6 and AOA to 40 deg for all configurations. For body alone and wing-body cases, it has been validated to 90 deg AOA. Additional test data or Navier Stokes computations would allow refinement of the improved method. The new method has been compared to several existing techniques. The method was found to be as good as or better than existing techniques, but more general than existing methods in terms of configurations and Mach numbers allowed for the method to be used.