Suppression Of Marangoni Convection Of Silicon Liquid Bridge By A Non-contamination Method

A non-contaminating method which is characterized by the introduction of Argon gas, which was flown tangentially over the silicon melt free surface, producing a viscous shear drag opposing the Marangoni shear at the free surface was demonstrated valid to suppress the Marangoni convection(MC)in a silicon liquid bridge under micro-gravity. The physical and mathematical models are founded. Numerical simulation of Marangoni convection in the liquid bridge and gas channel was performed by employing the primitive variable method and using Galerkin finite element method, which is applied for discretization of non-dimensional governing equations and boundary conditions. The relationship between the suppressing status of MC in the liquid bridge and the inlet gas velocity or the channel width is obtained, and the suppressing status of some kinds of Marangoni numbers(Ma) or size ratios of liquid bridge A is analyzed.The results show: The reductive effectiveness is associated with the inlet gas velocity for a given conditions. By choosing the optimal gas velocity, which may be determined by an obtained correlation which was acquired by our result, the best reductive effectiveness of Marngoni convection can be achieved. The best reductive effectiveness under different gas channel width, Marangoni number and aspect ratio have been represented. It should be emphasized that the MC reduction of 99% can be realized in some situations. The value of inlet gas velocity decreases and the reductive effectiveness of the MC increases when only decreasing the value of channel width. By changing the Marangoni number alone, we found that the less the marangoni number, the less the needed inlet gas velocity and the better the reductive effectiveness of the MC. If we change the aspect ratio(A) solely, an optimal reductive effectiveness of the MC can be gotten when A equals to 2.0We obtained the correlation between the inlet gas velocity and other non-dimenional factors, which will be helpful to the practical application.