فهرست مطالب mahmood tabaki

In this article, cavitation flow around axisymmetric projectiles with ringed and non-ringed cavitator has been investigated using control volume and boundary element methods. In the numerical method, the homogeneous equilibrium approach as well as the zwart model, for modeling the mass transfer and forming the system of equation, have been used. In the boundary element approach with dipole distribution on the body and cavity surfaces and source distribution on the cavity surface, the right conditions were set for using the Green's theorem in solving the potential flow. Moreover, some source components were imposed on the cavitator surface in order to add the hole effects. The validation procedure for both methods has been done by analytical and experimental data. In general, the results of this research are presented in two parts. In the first part, hydrodynamic properties of ringed cavitator such as cavity dimensions, intended forces, flow behavior and etc are analysed deploying the numerical methods based on Navier Stokes equations. In the second part, the boundary element method has been used for the analysis of the cavitation flow around practical geometries with ringed cavitator. The most important finding of this study is reduction of the cavity dimensions and also an increase in the force on the projectile during the use of annular cavitator. In addition, as a result of this study, two equations for maximum length and maximum diameter of the formed cavity on the cylindrical body in relation to the cavitation number and hole diameter have been provided.