Numerical Simulation on Hydrodynamic Characteristic and Cavity Form around High-speed Projectile

The exact acquirements of hydrodynamic characteristic and cavity form of high-speed projectile underwater mainly affected by angle of attack,are the precondition to study the stability of its trajectory.To research the influence of coupling caused by the change of angle of attack between hydrodynamic characteristic and cavity form of projectile on trajectory stability,three-dimensional numerical simulation model of natural supercavitation was built.The hydrodynamic characteristic and cavity form of projectile with various angles of attack were analyzed,and the law was obtained.Results have showed that in the case of small angle of attack,the hydrodynamic coefficients change linearly,and the critical angle of attack of projectile is larger than that of self-reliance supercavitating vehicle.The cavity thickness of downwind side and off-axis changes obviously with varying of angle of attack.The conclusion of this paper will provide a theoretical foundation for further study on the stability of the projectile trajectory.