Hyper-X Hot Structures Comparison of Thermal Analysis and Flight Data

ABSTRACT The Hyper-X (X-43A) program is a flight experiment to demonstrate scramjet performance and operability under controlled powered free-flight conditions at Mach 7 and 10. The Mach 7 flight was successfully completed on March 27, 2004. Thermocouple instrumentation in the hot structures (nose, horizontal tail, and vertical tail) recorded the flight thermal response of these components. Preflight thermal analysis was performed for design and risk assessment purposes. This paper will present a comparison of the preflight thermal analysis and the recorded flight data. INTRODUCTION The Hyper-X program is designed to build and test a scaled airframe integrated airbreathing propulsion configuration. Goals of the flight experiment are to demonstrate scramjet performance and operability under controlled powered free-flight conditions at Mach 7 and 10. The Mach 7 flight was successfully completed on March 27, 2004 and the Mach 10 flight is scheduled to fly in the fall of 2004. The Hyper-X research vehicles are boosted to the required test conditions with a modified Pegasus booster launched from a B-52 carrier aircraft. The flight experiments provide flight data for correlation of ground test data and predictions, experimental techniques and analytical methods for future use in hypersonic vehicle design. Stability and control of the Hyper-X research vehicle is handled by all-moving horizontal tails and vertical rudders that must survive the high aerothermodynamic heating trajectory. The horizontal and vertical tails, along with the vehicle nose are directly in the air stream and undergo substantial heating that can produce large thermal gradients. The purpose of the aeroheating and thermal analysis process was to predict the probable heating loads on the hot structure components and the resultant temperatures. From these temperatures and gradients, a structural analysis could be performed which would demonstrate the deflections and stresses in the material. The temperature predictions are used to verify that all materials remained within their usable temperature ranges. Thermal analysis of a hypersonic vehicle poses many distinct challenges. The high aeroheating environment demands that the thermal model be robust, and respond well to high loads, abrupt transients and extreme surface fluxes. The material properties must accurately reflect the physical system both in terms of directionality and property variation with temperature, since thermal excursions may be large. The aeroheating environment must be captured accurately, and