相变发汗冷却可用于飞行器端头等局部极高热流区域的热防护。超高速条件下端头相变发汗冷却涉及复杂的物理过程，亟需建立高保真计算方法，揭示端头相变发汗冷却中的复杂流动干扰机理以及传热机理。本项目将建立耦合发汗的主流多组分扩散界面两相流方法，通过全速域黎曼求解、基于自动微分全隐式离散技术，发展高效准确的方程数值离散方法。针对高梯度、非均匀气动加热导致的发汗冷却剂渗流通道选择、相变蒸发非均匀特性，以及气-液干扰流动特性，建立内外流双向耦合模型，对其流动机理、传热机理开展深入的科学研究。该项目的完成将有利于揭示双向耦合端头相变发汗冷却内外流干扰及传热机理变化，可以为我国临近空间高超音速空间飞行器、再入飞行器等的气动设计和防热设计提供强有力的计算方法支撑。

The thermal protection system by transpiration cooling with coolant phase change can be used in areas of extremely high heat flux, such as the nosecone of hypersonic vehicles. The physical process involved in the transpiration cooling with coolant phase change on nosecone is very complicated. It is urgent to establish a high-fidelity numerical algorithm to reveal the complex flow mechanism and thermal transfer mechanism in this specific transpiration cooling process. This project will address the complex physical process of transpiration cooling with a coolant phase change at nosecone, and develop an multicomponent two-phase algorithm simulating the high speed main flow with coolant. An efficient and accurate numerical methods by introducing full-speed Riemann solver, fully implicit discretization based on automatic differentiation technology is introduced as well. To simulate the phenomenon by extremely high-gradient, non-uniform aerodynamic heating, which lead to non-uniformity coolant movement and redistribution; and the phase change evaporation process leading to gas-liquid interference , a high-fidelity model with a bi-directional coupling of internal and external flow is established, and in-depth research on mechanism of transpiration cooling at the nosecone will be conducted. The completion of this project will be helpful to reveal internal-external flow interference and heat transfer mechanism of the transpiration cooling with a coolant phase change at nosecone, which can provide an effective tool supporting the aerodynamic design and thermal protection design of near-space hypersonic vehicles or reentry vehicles.