Numerical Simulation on Inter-stage Separation of Finned Launch Vehicle

Abstract The stage separation of large launch vehicles has always been one of the most dangerous phases in the entire launch process, a fast and safe separation process will greatly increase the reliability of the entire launch system. A novel finned inter-stage separation structure for launch vehicles was proposed. The compressible N-S equation and six degree of freedom rigid body motion equation were solved by a coupled pressure-based solver combined with a second-order upwind scheme to simulate the separation process. The influence of different fin distribution during the separation process was studied. The results show that the finned inter-stage separation structure can reduce separation time by nearly 40%, and increase the backward force by 23.7 times; Under the premise of equal fin area, number of fins doesn’t affect the pressure distribution on each fin, only affect its peaks; The finned structure can increase the stability of the launch vehicle, allowing it to separate normally under initial interference of up to 5 degrees per second. The research results can provide references for the development of separation technology for launch vehicle to a certain extent.