2005 Version of the Aeroprediction Code (AP05)

Abstract

A new version of the aeroprediction code (APC), the AP05, has been developed. The AP05 addresses additional emerging projectile and weapon needs not met by the former version of the APC, the AP02, along with providing additional productivity and user flexibility options. Some of the new elements of the AP05 include three-fin aerodynamics capability, trailing-edge wing bluntness effects on normal force coefficient, truncated fin leading-edge and body-nose bluntness improvements on axial force coefficient, improved two-dimensional base pressure coefficients for fins, and small caliber weapons capability. Some of the improved productivity and user flexibility options include trim aerodynamics, protuberance aerodynamics input options, increase in altitude limits for trajectory simulations, and user-defined boundary-layer transition for the body and wing. In addition, several errors in the AP02 were corrected for the AP05. Approximately 50 cases were considered for comparing the AP05 aerodynamic predictions to the AP02 and experimental data. It was found that the AP05 gave improved accuracy over the AP02 compared to the experiment for those areas where new elements had been incorporated into the AP02 to form the AP05 and where errors in the AP02 were corrected. However, for those cases where the new elements of the AP05 were not utilized, similar accuracy of the AP02 and AP05 codes compared to experimental data was seen. Several of the new elements of the AP05 were seen to improve productivity substantially over the AP02, the most significant being the automation of trim aerodynamics. The AP05 is, thus, the most accurate and robust of the APCs produced to date.