Numerical Simulation Of 3D Fluid Field In Electromagnetic Shaping

Electromagnetic shaping and directional solidification is a new materials preparation technology combined with technologies of electromagnetic and directional solidification. It makes melting and shaping with no model being possible. The aims including increasing temperature-gradient and cooling-rate, fining structures and avoiding pollution are realized to advance materials performances largely. In the processing of electromagnetic shaping, the distribution of fluid, fluid rate at S/L interface and free surface affect the growth mode, structure of performance, stability in shaping process and surface quality directly.This paper makes use of the method of numerical simulation to analyze the fluid distribution and fluid rate with effect of electromagnetic force in the processing of electromagnetic shaping.At first, an appropriate mathematics model with reasonable approximation and hypothesis was selected through analyzing the fluid of melt in processing of electromagnetic shaping. A function of generalized fluid was used to treat the trouble of mush zone. According to the actual case, a suit of schemes were brought forward to treat the boundary condition of rate. The momentum functions and fixed pressure functions were discretized using the SIMPLE algorithm and combining with the function of controlled volume.Secondly, the numerical simulation programs of 3D fluid field have been worked out. An index system of interleaving variables was established to reduce enormously the troubles brought after importing the frame of interleaving mesh. A technology for compressing the sparse matrix consumedly was created. The SOR iteration was improved through combing with this technology. It increases the program efficiency enormously.At last, some examples were calculated with the programs. The results illustrate:In the tabular melt, the distributions of fluid are all double-eddies with different technical parameters. The rules of fluid rate with different technical parameters: the increase of electromagnetic force causes the increases of the fluid rates at S/L interface and free surface, the decrease of skin depth, the increase of electric current density which will make the fluid at free surface flowing faster, while it doesn't affect the fluid rate at S/L interface. When the height of melt increases, the both of fluid rates will increase too. The increase of the width-thickness ratio augments the fluid rates along the wider edges at S/L interface evidently, while the rates along the narrow edges will have little change, and the rate at free surface has little change too. The increase of overheat degree minishes the range of mush zone, while the fluid rates at S/L interface and free surface will increase evidently.The calculated results conform to the phenomenon in experiments. It can guide the direction of experiments for future.