Numerical Simulation Method For Multiphase Compressible Cavitating Flow

The cross-media vehicles are capable of flying at high speed and possessing excellent underwater stealth performance.It has become an importance field in navy equipment research.When running near the free surface,the surrounds of the cross-media vehicles are full liquid,natural cavitation,ventilated cavitation,incondensable gas and jet of propulsion system with complex interaction among them.It is difficult to accurately predict the unsteady cavity shape and hydrodynamics of the vehicle.In the current work,a multiphase compressible solver with high-precision interface capturing are developed for the complex cavitating flow.The coupled VOF&Level-set interface capture method and artificial interface compression technology,as well as several cavitation models and turbulence models,are implemented in the solver.Efforts have been to test and optimize the parallel performance of the solver.By removing the redundant communication,the strong scalability of the optimized solver improves by four times and the speed-up performance improved by 2.76 times finally.Validation cases show that the solver has a good computation accuracy.In order obtain precise mass transfer rate during the cavitation progress,a SAO based calibration method is developed for cavitation model empirical parameters,which turns out to be rapid and efficient.The calibrated parameters has a good performance in cavitating flow simulations.Based on the developed solver,simulations of the natural cavitation and ventilated cavitation on the base ventilated hydrofoil are carried out.The interactions between the two types of cavity,as well as the deformation mechanism of the ventilated cavity,are discussed in detail.Finally,water tunnel experiments and numerical simulations are carried out to studied the evolution of ventilated cavities and jets.Interaction between them is also studied.The numerical simulation results suggest that the vortex structure generated by the jet is the initial cause of the deformation of the ventilated cavity interface.Potential solutions also have been discussed for undermining or eliminating the influence of jet on the ventilated cavity.The results of this paper could would push forward the numerical simulation method for complex cavitating flow.It also has a significant impact on the development of the cross-media vehicles.