Aerothermodynamic Environment for a Generic Missile

There are a variety of computer codes of varying degrees of rigor that can be used by the designers of high speed missile systems to define the aerothermodynamic environment at flight conditions. It is assumed that the flow models and the numerical algorithms used in these codes have been validated by their developers. However, the users of such codes must exercise them against a quality database, gaining knowledge of the intricacies in the use of such codes and calibrating the range of conditions over which the code can be used to predict specific parameters that are important to the design objectives without necessarily verifying that all of the features of the flow are correctly modeled. Forces and moments, surface pressures, surface temperatures, and flow-visualization photographs have been obtained in the Tri-Sonic Wind Tunnel at the USAF Academy at Mach 4.28. When comparing the flowfield parameters computed using state-of-the-art codes with the corresponding experimental parameters, streamwise oscillations were observed in the computed pressure distribution on the windward surface of the missile at angle of attack. These anomalous results were eliminated by modifying the grid to cluster points for capturing the bow shock wave. (Author)