Abstract: It is difficult to conduct the ground separation test of large-scale rocket fairings under vacuum condition. To predict the fairing separation during extra-atmospheric flight, the established finite element (FE) model should be corrected by using the ground separation test data. The ground separation test of a large-scale flexible fairing is simulated by the coupled Eulerian-Lagrangian method. The motion characteristics and breathing deformation data of fairing separating under air resistance are obtained and agree well with the test data, which verifies the correctness of the model and the method. The separation of rocket fairing during extra-atmosphere flight is simulated with the same FE model, and the effects of air resistance and axial overload on fairing separation and deformation characteristics are analyzed. The results show that the air resistance attenuates the velocity and breathing vibration frequency of rocket fairing, but increases the amplitude of the breathing motion; the amplitude of breathing motion increases with the increasing in axial overload, meanwhile, the breathing motion of fairing is related to the first-order vibration mode. Key

Key words: launchvehicle, fairing, rotationalseparation, breathingmotion, fluid-structurecoupling