Numerical assessment of double lateral jets interaction in rarefied nonequilibrium crossflows via nonlinear coupled constitutive relations

Abstract

Compared to traditional aerodynamic control surfaces, the reaction control system (RCS) offers enhanced control maneuverability for hypersonic vehicles at high flight altitudes with a low-density effect. However, the interaction of double lateral jets in a rarefied nonequilibrium flow yields intricate flow phenomena, markedly affecting the performance analysis of RCS. In this study, the nonlinear coupled constitutive relations (NCCR) model, regarded as a promising and efficient approach for modeling rarefied nonequilibrium flows, is utilized to investigate the influence of double lateral jets on a typical hypersonic cone-cylinder vehicle at 80 km under different jet states. The results show that the low-pressure region aft of the first (auxiliary) jet exerts an attraction effect on the shock wave structure generated by the second (main) jet when both jets are active, altering the surface pressure distribution in the middle region. Specifically, the attraction effect reduces the high-pressure peak of the main jet, expands the area influenced by the wrapping effect, and disperses the disturbance of the wrapping effect on the wall, indicating that the implementation of an auxiliary jet at suitable positions can enhance the ejection process of the main jet and diminish the side effect of the RCS. Additionally, a lower surface pressure distribution especially near the jets is calculated using the NCCR model against NS equations, accentuating the influence of rarefied gas effect on lateral jet interactions. These findings highlight the engineering potential of the NCCR model for investigating complex flow phenomena behind multiple jets interaction in rarefied nonequilibrium crossflows, providing suitable calculation tools for the RCS design of hypersonic vehicles.