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为了揭示错位Rushton桨的混合机理,采用计算流体动力学方法,对层流和湍流水动力学特性进行了研究.首先通过与文献中实验结果的比较,验证了所建数值模型及模拟方法的可靠性,然后重点分析了错位桨搅拌槽内的尾涡、流场和搅拌功耗.结果表明:与标准Rushton桨相比,相同转速时,错位桨能减小尾涡尺寸,降低搅拌功耗,而且桨叶宽度越小越有利,但过低的桨叶宽度不利于增大流体速度及速度分布的均匀程度.相同搅拌功耗时,桨叶宽度为3 D/20和D/5(D为搅拌桨直径)时错位桨的搅拌效果明显优于标准搅拌桨,两者对流体速度提高的幅度相当,但桨叶宽度为3 D/20时的尾涡尺寸小,故为推荐桨叶宽度.
In order to reveal the mixing mechanism of the misaligned Rushton paddle, the computational fluid dynamics (CFD) method was used to study the laminar and turbulent hydrodynamic characteristics.Firstly, by comparing with the experimental results in the literature, the numerical model and the simulation method were verified to be reliable The results show that, compared with the standard Rushton propeller, the dislocation propeller can reduce the size of the wake vortex and reduce the power consumption of stirring when compared with the standard Rushton propeller, The smaller blade width is more advantageous, but the too low blade width is not conducive to increasing the uniformity of fluid velocity and velocity distribution. The blade width is 3 D / 20 and D / 5 (D is When the paddle width is 3 D / 20, the vortex shedding size is small, so it is the recommended paddle width.