Effect of Impeller Speed Perturbation in a Rushton Impeller Stirred Tank
Effect of Impeller Speed Perturbation in a Rushton Impeller Stirred Tank
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Rushton 叶轮搅拌槽中叶轮速度扰动的影响
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
S. Acharya
中科院分区：
文献类型：
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作者：
Somnath C. Roy;S. Acharya
采用与时间相关的叶轮转速对无挡板Rushton-叶轮搅拌釜式反应器(STR)内的流动进行了摄动。大涡模拟(LES)结果表明，与等转速情况相比，扰动增加了叶轮射流的宽度。扰动流中的湍流脉动增强，表现出较高的湍动能产生值和对流动能。研究了扰动周期内平均流场的变化。观察到在扰动情况下，尾缘涡在径向和方位向传播得更远。在扰动情况下，湍流动能的产生与叶轮射流的破碎有关。湍流动能的耗散由于微扰而增强，从而确保了分子尺度上更好的混合。
Flow inside an unbaffled Rushton-impeller stirred tank reactor (STR) is perturbed using a time dependent impeller rotational speed. Large eddy simulation (LES) revealed that the perturbation increased the width of impeller jet compared to the constant rotational speed cases. The turbulent fluctuations were also observed to be enhanced in the perturbed flow and showed higher values of production and convection of turbulent kinetic energy. Changes in the mean flow-field during the perturbation cycle are investigated. The trailing edge vortices were observed to propagate farther both in the radial and azimuthal direction in the perturbed case. Production of turbulent kinetic energy is observed to be related to the breakup of the impeller jet in the perturbed case. Dissipation of turbulent kinetic energy is augmented due to the perturbation ensuring a better mixing at the molecular scale.