Numerical study of a new scheme of self-adaptive transpiration cooling

Phase change transpiration cooling based on the porous structure is one of the most potential thermal protection technologies. Compared with an active transpiration cooling system, a self-adaptive transpiration cooling system does not need additional pressure devices, which reduces the instability factors and the system's weight. Utilizing the properties of liquid phase change that generates high-pressure vapor, which expands spontaneously, this paper proposes a new self-adaptive transpiration cooling scheme with liquid phase change. To evaluate its feasibility, reliability, and cooling capability, a mathematical model and corresponding numerical strategy are firstly established and validated by theoretical analysis, then are used in simulations of transient characteristics of fluid flow and fluid–structure coupled heat transfer in the self-adaptive transpiration cooling process with various operating conditions. The analysis indicates that the self-adaptive transpiration cooling system can successfully realize the self-generation and self-pumping of vapor flow within the structure and keep vapor flow stable and timely response to time-varying heat flow. Moreover, with the shortening of structure length, self-generation of vapor flow and cooling performance are significantly strengthened and are gradually approaching their optimal states, which verifies this new cooling scheme's extremely high cooling potential.