Boundary-Layer Transition and Surface Heating Measurements on a Hypersonic Inflatable Aerodynamic Decelerator with Simulated Flexible TPS

摘要

The aerothermodynamic environment of a Hypersonic Inflatable Aerodynamic Decelerator (HIAD) with a Flexible Thermal Protection System (F-TPS) has been investigated through wind tunnel testing. Boundary-layer transition onset locations and surface heating distributions were measured using global phosphor thermography on deflected, solid-surface models representative of a HIAD aeroshell with a flexible surface. Data were obtained at Mach 6 for a wide range of surface deflection heights, angles of attack, and free stream Reynolds numbers. The surface deflections resulted in earlier boundary-layer transition onset and higher heating levels than for a smooth-wall surface, with the greatest effects occurring on the leeward side of the aeroshell. The heating augmentation and transition onset data were correlated using flow field properties obtained from a complementary computational study. A method was developed to estimate F-TPS deflection effects using these correlations along with smooth-wall flow field predictions. This method was validated through comparisons to the wind tunnel data and then used to generate post-flight predictions for aeroshell heating levels of the IRVE-3 flight test program. The results of this study provide a means for estimating F-TPS deflection effects for future flight tests, as well as an experimental database for use in the development and validation of computational methods for simulations of HIAD aerothermodynamic environments.