Numerical Simulation Of Foundry Process Based On Smoothed Particle Hydrodynamics

Casting simulation technology has been widely applied in actual production after continuous development.Most of the casting simulation software used are based on the grid method(FDM,FEM,etc).At present,it is used to calculate the single phase metal fluid flow.It is difficult to deal with the problems of deformation boundary,motion interface and multiphase flow.The SPH(smooth particle hydrodynamics)method can deal with such problems well.In this paper,the SPH method is used to research the numerical simulation of casting process following aspects.First of all,learning the basic contents of SPH method,and several correction methods of SPH method are cited to improve the stability of computation.For the boundary problem of SPH method,we use the simply and effectively penalty function boundary with physical attributes.The foundry program of SPH method has been completed independently,and the filling of typical examples of ring part has been calculated.The calculated results are consistent with the experimental results,which is the foundation for numerical simulation research of casting process based on SPH method.Secondly,in order to solve the actual casting process of gas-liquid two-phase flow problems,Setting up surface tension model based on the existing procedures,the surface proved is correct by square droplet rounding calculation result;we deal with the gas-liquid two-phase large density difference motion problem by calculating the bubbles case comparison results with the experimental process,so verified the SPH calculation method for large densitydifference of gas-liquid two-phase flow is feasible;SPH method applied in the bottom water injection cavity simulation,the calculation results are consistent with experimental results,proved the correctness of the SPH method to calculate the filling simulation of gas-liquid two-phase flow,gas volume provide a solid foundation for defect prediction in the casting filling process.Then,numerical simulation of casting process of the temperature field is searched by the SPH method,the heat conduction equation is derived from the study of Cleary and dispersed by SPH method,use the SPH method to establish the heat conduction equation verified the accuracy by flat wall heat conduction temperature value consistent with the analytic solution;casting solidification process of phase change latent heat is crucial problems,based on the above procedure,adding modified temperature recovery method model Procedure,then the temperature field of L type aluminum alloy castings is calculated.the calculation results compared with the casting simulation software Win-cast,proved established the temperature field model correctness,accuracy by the SPH method.Finally,Research on shrinkage defect prediction by the SPH method,the shrinkage defect prediction model and virtual particle model program are established,the particles that reach the shrinkage condition are transformed into virtual particles;Then calculation of cylindrical cast steel is calculated,the calculated results are basically consistent with the laboratory results by location and size of the shrinkage cavity,which verifies the practicability and accuracy of the SPH method for prediction of shrinkage defects.