Transient Numerical Study on Drag Reduction and Thermal Protection Characteristics of Porous Reverse Jet in Deployable Reentry Vehicles

In recent years, hypersonic vehicles have become a hot topic in the current aerospace field. Hypersonic reentry vehicles are faced with tremendous resistance and severe aerodynamic heating during the reentry process, making drag reduction and thermal protection of the vehicle the focus of design. Among the various new drag reduction and thermal protection methods, the use of reverse jet flow stands out for its advantages of not altering the aerodynamic shape of the vehicle and adjustable control. This paper focuses on the drag reduction and thermal protection issues of a deployable mechanical aerodynamic vehicle and carries out transient numerical simulation of the reverse jet flow to explore the drag reduction and thermal protection characteristics of the reverse jet flow scheme. The simulation of the establishment process of single-hole and multi-hole reverse jet flow fields is conducted to obtain a clear transient structure after the jet flow is initiated, compare the flow field characteristics under pressure gradient changes, and obtain aerodynamic and thermal parameters over time, revealing the "positive/negative delay effect" of the transient jet flow. By comparing different schemes, a jet flow scheme with superior overall drag reduction and thermal protection effects is obtained, laying the foundation for further engineering applications of reverse jet flow in vehicles.