基于CFD的管式膜过滤过程的流体动力学研究

Fluid dynamics of tubular membrane filtration process based on CFD

通过CFD数值计算的方法,采用达西定律和k-ωSST模型,对管式膜在80kPa恒定出口压力、不同流量下的过滤过程进行了流体动力学分析,揭示了其内部的流动规律,经试验验证,模拟计算结果与实验值吻合较好.分析结果表明:流量越大对膜内壁面的冲刷能力越强、涡旋扰动越剧烈、渗透流量越大、跨膜压差也越大,膜管内随着轴向距离的增加压力呈线性减小的趋势,压力值线性减小的斜率k随着流量Q(L/h)的增加而减小、基本符合k=-0.012 5 Q的关系.

Using the method of CFD numberical calculation,tubular membrane fluid dynamics analysis was carried out under 80 kPa constant pressure different flow rates by darcyrs law and k-ω SST model, reveals its internal flow rule, after experimental verification, simulation results are in good agreement with theexperimental value. The analysis shows that, when flow rate increases, the wash on membrane wail surface is stronger, Vortex disturbance is more intense, seepage flow is greater, transmembrane pressure difference is bigger. In the membrane tube the pressure decreases linearly with the increase of the axial distance, the slope of the linear decrease k decreases with the increase of Q （L/h）, conform to the relationship of k=-0. 012 5 Q.