Cooling characteristics of opposing jet-transpiration cooling combined system with variable mass flow rate distribution

Abstract

To address the extreme thermal load challenges faced by aerospace vehicles, one of the promising solutions is the integration of multiple cooling techniques through combined cooling technology. To further enhance the efficiency of this combined cooling approach, this study employs numerical simulations to analyze the effect of multi-chamber injection strategies on the efficiency of opposing jet (OJ) - transpiration cooling (TC) combined cooling. The research reveals that the multi-chamber injection strategy exhibits a significant advantage compared to the baseline injection method in terms of thermal protection at the leading edge. Specifically, when the coolant distribution is optimized to 10 g/s for TC and 15 g/s for OJ, the peak and average temperatures at the leading edge are reduced by 17.47 % and 10.22 %, respectively. This strategy optimizes coolant distribution along the vehicle's leading edge, significantly modulating the interaction between the coolant and the mainstream, and utilizes the convective heat transfer characteristics of the porous matrix more effectively. The study further demonstrates that dynamically adjusting OJ and TC injection rates based on the thermal load distribution can achieve more effective thermal protection. For regions of high thermal load, like the stagnation point on the leading edge, increasing the coolant mass flow rate on the OJ side can achieve more effective thermal protection, whereas for low thermal load areas, a high-efficiency TC injection strategy is more appropriate. These findings provide a valuable theoretical basis and technical guidance for the design and optimization of thermal protection systems in aerospace vehicles.