Research on the influence of swing on side-load in rocket motor

Side-loads in nozzle can cause serious structural damage. Owing to the presence of the inevitable swing nozzle in the actual environmental situation, the unsteady flow field of the swinging nozzle, which is based on dynamic mesh technology, was simulated by taking VOLVO S1 nozzle as the object of study and adopting CFD numerical simulation method. Meanwhile, a multi-faceted computing research was conducted on the restricted shock separation (RSS) at NPR=16. The internal nozzle flow separation and side-loads were analyzed under different swing states. The result shows that nozzle swing has notable effect on side-loads in nozzle, which is mainly embodied as the followings: Side-load enhances first, then decreases later with swing frequency. The loads attain the maximum while nozzle swing frequency approaches the frequency of flow separation. Side-load increases linearly with swing amplitude. Besides, the research on the analysis of side-loads in different swinging working conditions shows that side-load mainly comes from the convergent part.