Coupled Simulation of Hot Stage Separation with Adaptive Mesh Refinement

The stage separation process, though often completed within one second, plays a critical role in determining the overall success and safety of the launch mission. The process of host stage separation is simulated to study the flow field evolution and the impact on the lower-stage. Overset mesh is utilized together with a novel adaptive mesh refinement sensor for the purpose of adapting to the relative motion. A third-order scheme is adopted in spatial discretization, and the simulation results fit well with the experiment data. The results show that the initial shockwave oscillated back and forth in the cavity of the lower-stage, leading to sustained oscillations in the forces of the lower-stage. Based on the monitor data, the force acting on the lower-stage exhibits five phases. Compared with former research, a longer interstage results in two more obvious oscillation phases. The pressure distribution on the forward dome of the lower-stage is also studied.