Research progress on the failure modes and failure mechanisms of the transpiration cooling structure

As the speed of flight increases, high-speed vehicles experience enormous thermal loads when flying through the atmosphere, rendering traditional passive cooling techniques insufficient. Transpiration cooling, as an efficient active cooling technology, offers a cooling capacity of up to 10³-10⁵W/cm², with demonstrated advantages over other active cooling methods: it reduces coolant consumption by approximately 2/3 compared to convection cooling, achieves 35% higher cooling efficiency than regenerative cooling at equivalent coolant injection ratios, and reduces structural weight by 8.6% relative to convection cooling systems. Furthermore, the technology demonstrates remarkable shape adaptability. However, despite its potential, the technology still faces several failure issues in technical applications, which hinder its use on high-speed vehicles. This paper provides a comprehensive review of the failure modes and failure mechanisms of transpiration cooling structures in high-speed vehicles. The failure modes are classified and summarized according to five aspects: the intrinsic properties of materials, pore structure uniformity, unique properties of the coolant, external factors of high-speed vehicles, and coolant supply methods. Regarding these failure modes, this paper further analyzes the underlying causes of each failure mode and prospects future research trends on failure issues. While transpiration cooling technology holds great potential for the thermal protection of high-speed vehicles, overcoming these challenges remain essential to improving its efficiency and ensuring reliable performance.