Model and Simulation of Two-Phase Transpiration Cooling Process for Aero-Engine Thermal Protection

The enhancement of performance in advanced aero-engines is limited mainly by the cooling efficiency of high-temperature components. The investigation of transpiration cooling technology utilizing phase change has already been conducted for extremely high heat flux situation encountered in aerospace applications. This study provides valuable insights for aero-engines cooling systems. Theoretical models and numerical simulation algorithms have been developed to describe the flow and heat transfer phenomena in two-phase transpiration cooling. The transition from liquid to vapor phase is simulated using the two-phase mixture model, with governing equations of density, pressure, and velocity. The algorithm demonstrates good agreement with experimental results in the literature, with a maximum deviation not exceeding 10%. The analysis of the single-phase and two-phase transpiration cooling process were both conducted and the results shew that the two-phase transpiration cooling process utilizing water as the coolant is more intricate and excessive coolant injection may not necessarily improve the thermal protection effect at the leading edge. Various factors influencing coolant flow, heat transfer, and phase transition must be fully considered, such as the thermal conductivity of the isotropic porous media structure and the isotropy of porosity. This work represents an initial exploration of the implementation of two-phase transpiration cooling in the thermal protection for aircraft engines, and the developed numerical simulation method exhibits high accuracy and usability.