刚柔组合搅拌桨强化流体混合的流固耦合行为

传统刚性搅拌桨通过对流体的剪切作用实现能量的传递,而刚柔组合搅拌桨可通过其多体运动行为强化能量传递。基于搅拌桨桨叶与流体之间的耦合运动作用,结合ANSYS Workbench仿真平台,采用双向流固耦合方法,模拟计算了刚性搅拌桨与刚柔组合搅拌桨桨叶的等效应力和总变形量,研究了流场的宏观结构;并通过测定混合时间和计算搅拌桨功耗对比分析了两种不同搅拌体系的混合行为。结果表明:刚柔组合搅拌桨使体系的混合时间缩短了近32%,搅拌桨功耗下降了7%,其桨叶尖端的变形量是刚性搅拌桨的10⁵倍,其应力比刚性搅拌桨增加了83%;与刚性搅拌桨相比,刚柔组合搅拌桨在流固耦合作用下对流体的作用力更大,能够更好地传递能量,增强流体运动,强化流体混合。

Fluid-structure interaction in liquid mixing intensified by flexible-rigid impeller

Traditional rigid impeller transfers energy by shearing action, while flexible-rigid impeller can intensify energy transfer by multiple-body movement. Based on the interaction between impeller and fluid, the equivalent stress and total deformation are computationally simulated for flexible-rigid and rigid impellers. Macroscopic flow structure is obtained by two-way fluid-structure interaction technique with simulation platform ANSYS Workbench, and the mixing effect in two stirred systems are discussed with measured mixing time and calculated impeller power dissipation. Compared with rigid impeller, the mixing time of flexible-rigid impeller system is decreased by 32%, its power dissipation is declined by 7%, its total deformation of blade tip is 10⁵ times larger, and its equivalent stress of blade tip is 83% greater, so that flexible-rigid impeller exerts greater force to fluid with the fluid-structure interaction, which contributes to energy transmission, liquid flow and mixing intensification.