Taylor-Couette流场数值模拟及絮凝效果研究

通过流体力学中的Fluent软件模拟了Taylor-Couette反应器的速度矢量分布、湍动动能分布和有效能耗分布,同时实验研究了TaylorCouette反应器不同内筒转速下三氯化铁对高岭土悬浊液的絮凝效能.结果表明,内外筒环隙间存在亚微尺度的涡旋,当转速为30～60 r·min-时,涡旋形状闭合完整,相互分离,涡旋内部速度梯度较小,湍动动能k在0.00010 ～0.00023 m2·s-2的范围内,有效能耗ε在0.00057 ～0.00189 m2·s-3的范围内,絮凝效能达到最大(80％以上),湍动动能和有效能耗过大或过小均不利于形成完整闭合的涡旋,絮凝效能较差.

Numerical simulation and flocculation efficiencies of Taylor-Couette flow

Based on Fluent technology, the numerical simulation of Taylor-Couette flow was performed, and the flocculation efficiencies were also obtained in the same Taylor-Couette flow at the different inner cylinder rotational speeds. The results indicated that the vortices of submicroscopic size were formed in the annulus gap as shown in the velocity vector map, and the velocity gradient inside the vortices was lower than outside vortices. When the inner cylinder speeds changed from 30 r·min^-1 to 60 r·min^-1, the flocculation efficiencies reached the maximum values (above 80%), the turbulent kinetic energy was in the range of 0.00010~0.00023 m²·s^-2, and the available energy dissipation rate was in the range of 0.00057~0.00189 m²·s^-3. Excessively high or low turbulent kinetic energy and available energy dissipation rate were not favorable for the formation of integrated and closed vortices, leading to lower. flocculation efficiencies.