Experimental investigation on transpiration cooling performance of porous ceramic with oriented channels

As a fundamental coolant carrier and heat transfer medium, the porous structure plays an important part in the transpiration cooling system. The transpiration cooling performance of SiC porous ceramic with oriented porous microstructure fabricated by the optimized biological template conversion technology has been thoroughly investigated based on the oxy-acetylene flame. This porous ceramic exhibits outstanding permeability and exceptional high-temperature resistance, enduring temperatures up to 1296 K. Meanwhile, it can achieve the remarkable and stable transpiration cooling performance across varying heat fluxes (2 MW/m², 3 MW/m², 4 MW/m²) and coolant flow rates (ranging from 12 g/miñ30 g/min). Additionally, a significant and interesting phenomenon that driving pressure exhibits an initial drop, followed by a rise, and then stabilizes as oxy-acetylene flame is exerted and removed on the porous ceramic filled with coolant (water) is found in the experimental process. Moreover, both saturation and contact angle exert a noticeable impact on the driving pressure, especially at small contact angle and low saturation, and the operational ranges of capillary force and driving pressure have been abstractly distinguished. This investigation can give the reasonable guidance for designing the porous microstructure applied in the transpiration cooling.