Numerical Simulations Of Vertical Centrifugal Casting’s Filling Process

As an efficient casting technique, centrifugal casting is widely applied in fields ofmilitary, exactitude apparatus, aviation and spaceflight. In recent years, centrifugal castingis playing such an increasingly important role in the foundry industry. The mould fillingprocess of centrifugal casting is more complex compared with ordinary casting technology.The engineers often develop the productive process based on their experience. Thetechnique of computer numerical simulation can be used to analyze the whole process ofthe centrifugal casting. Therefore, the rules of the filling process of the molten metal incentrifugal casting have been deeply researched by the way of computer numericalsimulation in this paper.In this paper, the critical technology of the centrifugal casting is illustrated. On thefoundation of the characters of vertical centrifugal casting, the shape of free surface andtwo kinds of the inertial force etc. are analyzed. Then the mathematics model for thefilling process of centrifugal casting is set up. To simulate the fluid flow of mould fillingprocess accurately and effectively, the Level Set method was introduced to describe theinterface movement between the gas and the liquid in the gas-liquid two-phase flowsimulation.The finite difference method (FDM) based on staggered grid is taken to derive thegoverning equations. The equation about the velocity field and the pressure field aresolved by Projection method, which simplifies the calculation process and raises thecalculating speed. For the accurately purpose, the third-order accurate Runge-Kuttamethod and the fifth-order accurate WENO scheme are applied to solved the Level Setfunction.An example with analytic solution of vertical centrifugal casting flow process issimulated to testify the accuracy of the mathematic model and the numerical method. Andthe numerical solution approximately coincides with the analytic solution, which indicatesthat the mathematic model is accurate. The mold filling of a complex part with thin-wall issimulated as well. The result shows that the Projection-Level Set method could simulate thin-walled casting effectively. A numerical example about Ti-alloy casting is simulated aswell. The simulation result of the rotational part indicates that the centrifugal pouring is anefficient way of filling, which is able to fill complicated thin-walled Al-alloy or Ti-alloycastings.The applications of the commercial software, such as the CFD software-FLUENT,and foundry simulation software-InteCAST in the numerical simulation of verticalcentrifugal casting are also discussed. The present study has a guiding significance to theproduction of vertical centrifugal casting.