应用格子Boltzmann方法直接数值模拟研究钢中夹杂物上浮及碰撞行为

Direct numerical simulation of inclusion floating and collision behavior in molten steel using the lattice Boltzmann method

采用格子Boltzmann方法对钢液中夹杂物上浮及上浮过程中的碰撞行为进行直接数值模拟研究.结果表明,不同尺寸夹杂物颗粒上浮速度的模拟结果和理论值基本一致,表明本文所采用的数值算法能够精确有效地对钢液中固相夹杂物颗粒运动行为进行研究.当钢液中直径为80μm的夹杂物颗粒位于直径为40μm的下方并一起上浮时,直径为80μm的夹杂物颗粒会逐渐追赶上直径为40μm的夹杂物颗粒并发生碰撞形成大尺寸凝聚体,凝聚体的上浮速度显著大于二者单独上浮时的上浮速度.对于直径为40μm的夹杂物来说,形成凝聚体后的上浮速度比单独上浮时的上浮速度增加300%.实际炼钢过程中,采取必要的措施增加夹杂物颗粒之间上浮过程中的碰撞凝聚,对于提高夹杂物颗粒的上浮速度,尤其是小尺寸夹杂上浮去除速度,提高钢液的洁净度具有重要的意义.

The floating and collision behavior of inclusions in the floating process was numerically simulated by using the Lattice Boltzmann method. It is found that the floating velocity simulation results of different size inclusion particles are almost the same as the theoretical value,which demonstrates that the motion behavior of solid inclusion particles can be investigated concisely and effectively by using the numerical algorithm adopted in this paper. When an inclusion particle with a diameter of 80 μm locates below an inclusion particle with a diameter of 40 μm and floats up at the same time,the inclusion particle with a diameter of 80 μm can catch up with the inclusion particle with a diameter of 80 μm,collide with each other and grow up into a big inclusion cluster. When the inclusion particles with diameters of 80 μm and 40 μm floats up separately,the floating velocity of the inclusion cluster is bigger than them. For the inclusion particle with a diameter of 40 μm,the floating velocity after collision with the bigger size inclusion particle increases by300% compared with that of floating separately. In the steelmaking process,it is necessary to take measures to enhance collision and coagulation in the floating process,which will improve the floating velocity of inclusions especially for small size inclusions and have a great importance on the cleanliness of steel.