Separation of an Ellipsoidal Body from a Two-Dimensional Ramp in Hypersonic Flow with Kestrel Validation

Abstract

This study investigated the separation dynamics of an ellipsoidal body shedding from a two-dimensional ramp using experimental and computational methods. The main objective was to assess the fidelity of computational simulations of a complex, interacting flow configuration via comparison with experimental data. Experimental data was generated by the HyperTERP shock tunnel at the University of Maryland. Ellipsoids were stationed on a 10° ramp with varying initial positions and were then exposed to Mach 6 flow, allowing them to fly freely in response to the aerodynamic forces experienced. Experimental results revealed three trajectory behaviors that were dependent upon the initial shock impingement location: expulsion to surfing, surfing, and direct entrainment. These behaviors were consistent with earlier sphere experiments, but the introduction of pitch resulted in somewhat more complex dynamics. Numerical simulations were performed with CREATE-AV Kestrel, the fixed-wing multiphysics tool developed by the Computational Research and Engineering Acquisition Tools and Environments (CREATE) Program. Computational results exhibited discrepancies primarily in terms of the velocity and acceleration values when compared to the experimental results. The sensitivity of the initial conditions caused unsteadiness at the start of the solution, and potentially propagated errors in velocity and acceleration downstream. Despite these initial errors, however, the computational simulations showed a comparable trajectory to those of the experimental results.