Study on high-speed water entry process of non-rotating vehicles

Abstract

The non-rotating trans-media vehicle can better adapt to the hypersonic flight conditions, but new problems in the hydrodynamic characteristics and motion stability arise during the water entry process. With the VOF multiphase model, Realizable k-ε turbulence model, and Schnerr-Sauer cavitation model, this paper establishes a simulation method of coupling the movement of non-roating body into water with multiphase flow fields based on overset grid technology, and the accuracy of the established model is verified. The simulation calculation of the oblique water entry process of the vehicle with different ratio of short axis to long axis in cross section is carried out. And the results show that although the ratio of short axis to long axis in cross section does not change the cavitation morphology, it affects the hydrodynamic and kinematic characteristics of the vehicle by influencing the relative position of the cavitation. As the ratio of short axis to long axis decreases, the motion stability of the vehicle increases gradually. However, if the ratio of short axis to long axis is too small, the drag reduction effect will be weakened, and the structure will suffer a bigger load.