On the nonlinear hydrodynamic characteristic of a ventilated supercavitating vehicle with high Froude number

The objective of this paper is to investigate the multi-factor-dependent and nonlinear hydrodynamic characteristics of a ventilated supercavitating vehicle with high Froude number, and further reveal the forming mechanisms of the complex hydrodynamic forces. A high-fidelity numerical model with the inhomogeneous multiphase model and SST k−ω turbulence model is established and validated by experimental results. Ventilated supercavitation flow has been performed over a wide range of angles of attack and gas entrainment coefficients. The results show that the wetting aft body leads to the increase of the gas-leaking rate and the decrement in the supercavity dimension, and the upper supercavity closure region gradually moves forward. Resultantly, the supercavity shape exhibits three distinct features with the angle of attack. The hydrodynamic characteristic of ventilated supercavitating vehicles depends on position relationship between the supercavity boundary and the vehicle. The hydrodynamic characteristic is more complex than that of natural supercavitating vehicles due to the joint influence of high pressure near the upper supercavity closure region, wetting area of the aft body and the variation in supercavity geometry. The hydrodynamic characteristics of the ventilated supercavitating vehicle can be controlled and improved by adjusting the gas entrainment coefficient.