For the numerical simulation of the mold filling process engineering
|School||Kunming University of Science and Technology|
|Course||Materials Processing Engineering|
|Keywords||mold fi11ing numerical simulation FVM SOLA Method conservative scalar method|
With the development of the computing technology and the numerical calculating technology,the compute was applied to the casting field more and more.The numerical simulation technology can simulate the forming process of mold filling, the solidification,the conduct heat,the stress field,the distribution of micro-organization and the shrinkage cavity and so on in the casting without experiencing practical moulding,and improve greatly the yield efficiency and economic benefits. Therefore, the compute technology has become important meanings in casting production.But in China, the study and application of the simulation technique in foundry process was still in quite backward stage, and the applied simulation softwares are few, especially in the numerical simulation of mold filling. The aim of the thesis was to research the numerical simulation of mold filling in the sand-molding foundry, and developed the correlative simulation software. The flow of the metal liquid can be regarded as the un-compressible Newton type fluid, So they still follow the law of conservation of quality, the law of conservation of momentum and the law of conservation of energy, we can set up the model equations of mathematics in view of the above laws, then apply with the conservative scalar equation to deal with the free surface problem, disperse these mathematics equations with Finite Volume Method, and calculate the dispersed equations to obtain the press field , the velocity field, the temperature field and the movement of free surface by the compute, then to forecast all kinds of disfigurements engendered from mold filling, such as the cold partition, the irrigation shortage, the engulfed air hole etc.The thesis adopted firstly FVM to disperse the model equations of mathematics at home and receive the finer effect. Although the FVM was applied more into the numerical calculation of fluid flow, the fluid on the casting is differ from the ordinary fluid, because it has highertemperature, slower speed, complex flow path etc.There were many algorithms to calculate the velocity field and the press field of fluid, but the thesis chooses the SOLA method after comparing the succesise, the convergence, the accounting time, and the resource engrossing the CPU.The thesis adopted the conservative scalar method to treat the free surface, for the conservative scalar method regards the double-phases mixture of gas and fluid as single-phase fluid, and calculate the entire flow field. Therefore, it need not bring to bear the boundary condition of free surfaces, can predigest the treatment of free surface greatly.On the basis of obtaining the velocity field and the pressure field, the various kinds of defects of mold filling can be visually predicted by adopting the after-treatment module of the solidification simulation software, and according to conservation of energy equation, the coupling temperature field can be calculated and provide the comparatively accurate initial-temperature field for the succedent solidification simulation.Finally, the software of mold filling was completed according to the algorithm of the thesis and utilized program C++. After compared the calculating result with the test data of the Benchmark, the result of water simulation filling experiment of the Lucite model and the result obtained by the similar successful business software, the result indicated the mathematics model, the computing technology of three-dimension flow field and the treatment method of the free surface of the thesis are correct basically. And the program can be applied triumphantly into the numerical simulation of the mold filling on the sand-molding foundry.