Transition of the flow type in the supersonic cavity controlled by the wall temperature

• Published in: The International journal of heat and fluid flow 2024-10, Vol.109, p.109549, Article 109549
• Main Authors: Gao, Zhan, Wang, Chenglong, Sun, Yongchao, Sun, Mingbo
• Format: Article
• Language: English
• Subjects: Flow type transition; Shear layer; Supersonic cavity; Wall temperature
• ISSN: 0142-727X
• DOI: 10.1016/j.ijheatfluidflow.2024.109549

•For L/D ratio of 13, the flow type transforms from a closed one to a transitional one.•The critical wall temperature is approximately 775 K.•As the incoming static temperature drops, the critical wall temperature declines.•Transition caused by the competition between the shear layer and recirculation zone.•Heat transfer is affected by the thickness of boundary layer or recirculation zone. The wall temperature of the high-speed aircraft increases quickly under hypersonic/supersonic incoming flow, which will cause a significant change in the flow structure. To study the transition of the flow type in the supersonic cavity controlled by the wall temperature, numerical simulations are conducted. The cavity length-to-depth ratio (L/D) is varied from 10 to 15, and the wall temperature ranges from 300 K to 1300 K. The results indicate that the type of cavity flow with an L/D ratio of 13 transforms from a closed cavity flow to a transitional cavity flow, when the temperature reaches approximately 775 K. And the transitional temperature rises with the elevated total temperature of the incoming flow. Furthermore, the mechanism of the cavity flow change with wall temperature could be the competition between the recirculation zone and the shear layer in the cavity. The rising pressure with higher wall temperature in the recirculation zone weakens the downward development of the cavity shear layer, preventing it from hitting the cavity floor. As a result, the mass exchange of cavity lip surface, pressure distribution, total pressure recovery coefficient, and heat transfer distribution in the supersonic cavity change dramatically. The critical wall temperature also affected by the sidewall effects and the inflow Mach number.