Thermo-structural Analysis And Design Of Hypersonic Vehicle Leading Edge

In order to improve the flight speed, flight maneuverability and lift-dragratio of hypersonic aircraft, sharp hot structure (SHS) is usually used instructural design methods. Sharp hot structure, such as nose cap and leadingedge, endure a very serious aerodynamic heating. Thermal protection becomes avery acute problem. Because of this service environment, ultra-high temperatureceramic matrix composites become to be requirements for the leading edge ofthe thermal structure of the alternative materials. This paper researches ondesign and analysis methods of thermal-structure of ultra-high temperatureceramic leading edge in service hypersonic environment.Temperature response and mechanical response analysis and calculationmethods of the leading edge is established. The key parameters in structuraldesign to is analyzed in this paper. The main factors which cause the structuralstress of leading edge are discussed. Heat stress is the combined effect oftemperature gradient and constraints. Compared with experiments, therationality and accuracy of the simplified model in numerical calculation isverified.Temperature field of the leading edge is obtained by finite element method,and then by sequential coupling numerical simulation the stress field ofstructure is obtained. From reducing leading edge thermal stress point of view,the material factors and structural factors affecting the design of thethermal-structure of the leading edge are analyzed quantitatively. Structuralshape parameters, material intrinsic characteristics, the mechanical boundaryconditions and the thermal matching performance are discussed.The maximum compressive stress in the large size leading edge is impactedby the width of leading edge significantly. Reducing the width of the horizontal segmentation splicing is an effective way to reduce the maximum stress. Twodifferent assembly design forms on the structure are discussed. That reduce theconstraint stiffness in the width direction of the block structure can reduce thetemperature gradient in the length direction, and ultimately effective to reducethe structural stress.