Numerical investigation on structural optimization for porous plate in transpiration cooling with phase change

There are problems between coolant space delivery and demand matching in transpiration cooling system, so improving the utilization of coolant by structural optimization for the system is of great necessity. Box-Behnken design (BBD) is carried out in this work based on the numerical simulation using a local thermal non-equilibrium (LTNE) model for transpiration cooling with phase change, during which liquid coolant vaporizes and absorbs a huge amount of heat. The regression equations for heated wall temperature and pressure difference inside the porous medium are obtained and used to quantitatively optimize the porosity, solid thermal conductivity and thickness of porous plate. The heat wall temperature is significantly impacted by porosity and solid thermal conductivity, where the square term of porosity is statistically significant in the regression equation analysis. The pressure difference inside the porous plate is mainly affected by the porosity and thickness of the porous plate. According to the regression equations between the three factors and two responses, an optimized porous plate featured with a porosity of 0.2, a thermal conductivity of solid of 45 W/(m & sdot;K) and a thickness of 9.04 mm is obtained, and the wall temperature and the pressure difference decline respectively by 3.55 % and 27.99 %.