Numerical Simulation Of Foundry Filling Process Using Smoothed Particle Hydrodynamics

As an important stage of filling process of casting molding, this process has greatly influenced the forming quality of castings. Many defects such as inclus ion cold shut and misrun are formed during filling process. Due to the conventional filling process is invisible, through the use of numerical simulation method to calculate and predict the filling process of liquid metal flow. we can optimize the design of casting process and parameters, the problem of quality of casting products, long trial period, difficulty in quality control and production costs can be overcome. The numerical simulation of filling process research has very important scientific value and application prospect. At present, most simulation for the macro filling process based on grid such as FEM and FDM methods, which are difficult to deal with problem of large mesh deformation and free surface capture. They can not deal with the process which have multiphase flow. Smoothed particle hydrodynamics(SPH) is a meshless particle method which have pure lagrange properties. It has great advantages to treat free surface, the interface movement and multiphase flow problems. The numerical simulation of SPH method in the casting research relatively less and require further research. so the numerical simulation method has a great development prospect. This paper mainly study the SPH method in casting process as the following aspects:The theory and calculation processes of SPH method are studied systematically. Conservation equations such as the mass conservation equation momentum conservation equation and energy conservation of fluid filling process are derived with SPH discrete form. Considering the characteristics in the casting process, we established the solid wall boundary partic le model,partic le search model,smoothing function choice, time integral calculation and etl. Based on the established SPH mathematical model and FORTRAN language, we developed a numerical simulation program of casting process. Through the established numerical simulation program, the plate casting filling process were calculated, the calculated results and the experiment results of casting filling process are compared and analyzed. The results of the particle density field was analyzed which in agree with liquid incompressibility characteristics. Moreover, the results are compared with the casting simulation software Win-Cast which proved have great advantages. The results of SPH calculation program,the experiment and Win-Cast proved the validity and reliability of SPH calculation program.Based on the SPH calculation program, study the multiphase flow in casting filling process. Study on the solid-liquid two-phase flow model, established mathematical model and computer program. A simplified particle cluster model with liquid metal filling process is simulated, analys is of the flow process of particle cluster model with the liquid metal, the simulation results and experiment results are compared. The particle cluster model is refined, the single partic les instead of partic le cluster model, analysis of the flow process of single partic le position field and velocity field with the liquid metal. The SPH numerical simulation program of solid-liquid two-phase flow is reliability.