关键词: 可重复使用, 火箭回收, 垂直再入, 热环境, 流动特性

Abstract: Reusable liquid-propellant launch vehicles constitute a pivotal direction for future space transportation systems. During vertical reentry, the aft-mounted engines descend in an irregular configuration facing the freestream, engendering highly localized and complex thermal environments. A simulation study of the flow over a Falcon 9 v1.2 derived geometry was conducted for four representative reentry phases: high-altitude powered deceleration, high-altitude aerodynamic deceleration, low-altitude aerodynamic deceleration, and low-altitude powered deceleration. Results demonstrate that the vehicle thermal environment is markedly transient and non-uniform: plume morphology evolves continuously with altitude and engine operating condition; powered phases exhibit substantially stronger flow disturbances and heat-flux maxima than aerodynamic phases owing to intense plume–freestream coupling; secondary combustion exerts a global thermal influence on the far-field plume at low altitude. Across all phases, peak heat flux consistently localizes at the nozzle-exit lip and the outer rim of the aft heat shield, reaching 380 kW/m2, thereby identifying these regions as critical for thermal protection.

Key words: reusable, rocket recovery, vertical re-entry, thermal environment, flow characteristics tracking