Transient Heat-Transfer Measurement Technique in Wind Tunnel and Data Analysis Technique Using System Identification Theory.

摘要

A transient maneuver testing technique has been developed by the Air Force Flight Test Center (AFFTC) for aerothermodynamic evaluation of the Space Shuttle Orbiter Thermal Protection System (TPS) during reentry. The objectives are to determine the feasibility of the testing technique and the feasibility of using the transient maneuver technique for wind tunnel heat transfer measurements. The transient maneuver technique can enhance the capability of wind tunnel testing by reducing the overall required testing time, and in turn lower the cost of testing significantly. Wind tunnel data were obtained using the TPS materials of the Orbiter as wind tunnel test articles. The principle finding indicates the heating estimates are significantly lower for the TPS test articles than the thin skin test article and Eckert theory. The discrepancy is believed to be caused mainly by the non-isothermal wall effect. Finally, the transient maneuver testing technique has been proven since the transient maneuvers agree well with the steady state results.