Numerical investigation on the transpiration cooling of three-dimensional hypersonic inlet

Abstract This paper presents a numerical investigation on the transpiration cooling scheme of three-dimensional hypersonic inlet with local overheat caused by shock/shock interaction using a simplified physical model. Through the analysis of the interaction performances including flow field structures, aerodynamic pressure and heating, two optimization strategies, i.e., gradient porosity layout and separated coolant chamber design are proposed, and five local-enhanced transpiration cooling designs are developed. To assess the feasibility of the optimization strategy, the cooling effectiveness, film covering effect, coolant allocation and driving characteristics of the five transpiration cooling schemes are then studied and compared with the conventional transpiration cooling. Results obtained indicate that: 1) the performance of conventional transpiration cooling scheme is weakened by shock interaction; 2) the optimized scheme with streamwise gradient porosity layout can effectively enhance the coolant allocation and lower the temperature in the whole stagnation region but at the cost of a higher coolant driving force, while the optimized scheme with spanwise separated coolant chamber design can only lower the temperature of the shock interaction area but can reduce the coolant driving force significantly; 3) combining the two optimization strategies, the coolant allocation on demand can be achieved without increasing the coolant consumption and driving force, the whole structure is protected effectively with relatively uniform temperature distribution.