镁合金双辊铸轧铸嘴内部熔体流动数值模拟

Numerical Simulation of Molten Magnesium Flow in Feed Tip Nozzles of Twin-roll Casting

分析了铸嘴内部分流结构对型腔内镁合金熔体流场、温度场产生的影响。采用有限差分的SOLA-VOF法,建立镁合金双辊铸轧立板过程中流动区域的三维流场与温度场耦合模型,在相同的铸轧立板条件下(前箱液面高度、前箱熔体温度固定),数值模拟了不同形状的铸嘴型腔结构对熔体流动速度及温度分布的影响。模拟结果表明,分流块的大小、形状及位置对温度场及流动场影响显著,采用小尺寸、多数量的分流块将有利于在铸嘴型腔内形成均匀的流动场和温度场。通过工艺试验,验证了模拟结果,根据模拟结果改进了铸嘴内部结构,使金属熔体流场、温度场分布均匀,获得了高质量的镁合金铸轧板材。

Effects of the configuration of feed tip nozzle on flow field and temperature field in twin-rolling casting strip of magnesium alloy melt in cavity were described. Based on the SOLA-VOF finite differential method,the coupled model of flow field with temperature field in twin-rolling casting strip of magnesium alloy melt has been established to simulate the effects of different nozzle cavity structure on flow velocity of the magnesium melt and temperature distribution in magnesium melt under the same initial condition including the same height and temperature of the molten magnesium alloy in front box. The results reveal that decreasing the size and increasing numbers of the spacer are helpful to obtaining uniformly distributed flow field and temperature field in cavity of feed tip nozzle. The results are well in agreement with simulated ones,and the magnesium alloy strip with desirable quality can be produced based on simulated results modifying the structure of feed tip nozzle.