液态金属中气体射流过程数值模拟研究

应用欧拉-欧拉法双流体模型描述液态金属中气体射流搅拌过程的两相流动及气泡分布.采用分别描述气泡和液体湍流的k-ε两相湍流模型,重点分析气泡和液体在流场中的受力,详细讨论了阻力、升力等相间作用力对气泡分布的影响.结果表明,气泡的喷射对熔池起搅拌作用,中心线上入口处气含率最高,进入熔池后迅速下降,到一定高度后下降趋势变缓,在出口附近趋于不变.预测结果和文献中的实验结果进行对比表明,在给出合理的相间作用力模型时,该模型预测值和实验结果符合较好.

Numerical simulation of turbulent flow processes of gas jetting into metal melt

The Eulerian-Eulerian two-fluid model was used to simulate the flow processes and bubble distribution of gas jetting into metal melt. A two-phase version of the k-e turbulence model was applied to the liquid and gas bubbles respectively. Effects of the inter-phase momentum exchange were examined with the emphasis on the influence of drag and lift forces. Results show that the metallic flow field in the ladle is stirred by gas injection, and that gas volume fraction decreases abruptly near the nozzle while it decreases gradually with increasing axial distance from the nozzle exit. Reasonable agreements between computational results and the experimental data from the literature were obtained by properly turning the drag and lift coefficients.