中文摘要：

利用计算流体力学数值模拟方法,对直段桨为双螺带式和Paravisc式以及底桨为锚式和变径双螺带式的组合桨功率和混合时间进行了研究,并对其中最优桨型进行了放大规律的探索。通过数值模拟得到了4种组合桨中各单桨及组合桨的功率准数关联式,提出组合桨中各桨之间功率上的反作用关系。在10种组合桨中,Paravisc-锚式组合桨达到完全混合时所转圈数最少,且在相同转速下量纲一剪切量较大,混合特性最优,将其从体积为100 L的搅拌槽内放大至200 L和500 L搅拌槽中,发现其符合桨端线速度的放大准则。文中对各桨型的功率特性、混合特性和放大规律的分析,可为工业设计和优化高黏度流体组合桨参数提供重要参考。

英文摘要：

The power and mixing efficiency of four types of impeller combination, including double helix and Paravisc as the main impeller, and anchor and variable-diameter double helix as the bottom impeller, were studied by CFD. And the scale-up of the optimal combined impeller was explored. The correlations of power number of the mentioned impellers were obtained and the power reaction relationship between two impellers was also proposed. Among the tested ten combinations, the Paravisc-anehor requires the least rotations to reach a full mixing, and has the larger dimensionless shear strain at the same rotational speed, showing the best mixing performance. In the scale-up of the tank with Paravisc-anchor from 100 L to 200 L and 500 L, it is found that the scale-up follows the tip linear velocity principle. The study provides important reference for the industrial design and optimization of combined impeller parameters of high viscosity fluid.