Dynamic characteristics of impeller of perturbed six-bent-bladed turbine in pseudoplastic fluid based on fluid-structure interaction

doi:10.11949/j.issn.0438-1157.20161651

Abstract

Abstract:

Dynamic characteristics ofimpeller of perturbed six-bent-bladed turbine (6PBT) and six-bent-bladed turbine (6BT) are analyzedcomparatively using bidirectional fluid-structure interaction (FSI) method based on simulation platform ANSYS Workbench. Macroscopic flow field structure and power consumption caused by the coupling action between the blade and fluid are studied, and the total deformation and equivalent stress distribution along the blade are also analyzed. Besides, the natural and prestressed mode of the 6PBT impeller are investigated comparatively. The results show that, compared with 6BT impeller, the tip deformation and stress of 6PBT impeller are increased by 8% and 61%, respectively, while its root stress is reduced by 6.7% with the well stress distribution of the blade along the radial direction, which indicates that the interaction force between 6PBT impeller and fluid is stronger, resulting in the faster energy dissipation, at the meantime, the blade strength is also improved. The vibration mode of 6PBT impeller under prestressed mode is consistent with that of natural mode, and the modal frequency has no significant changes on the prestressed action, which shows that the fluid-structure interaction and prestressed action have little influence on the blade mode. With the increasing speed, 6PBT impeller has an advantage with a better energy saving effect.

Key words: pseudoplastic fluid, 6PBT impeller, fluid-structure interaction, prestressed modal analysis

摘要：

基于ANSYS Workbench分析平台，采用双向流固耦合计算方法，对错位六弯叶搅拌器）6PBT）和六弯叶搅拌器）6BT）的动力学特征进行了对比分析，根据桨叶与流体之间相互耦合运动特性，探讨了宏观流场的结构和搅拌功耗特性，分析了桨叶的变形和等效应力分布，并对6PBT桨在静态和预应力状态下的模态进行了对比研究。结果表明：同6BT桨相比，6PBT桨叶端部变形量增加了8%，端部应力提高了61%，而根部应力降低了6.7%，应力沿径向呈均匀化分布，这表明错位桨对流体的作用力更大，能够更快地传递能量，同时桨叶强度也得到相应提高；6PBT桨的静模态与预应力模态振型分布一致，在施加预应力后模态频率无明显改变，说明桨叶流场的流固耦合作用和预应力对桨叶模态的影响不大；随转速的增大，6PBT 桨的节能效果显现，体现出错位桨的优势。

关键词: 假塑性流体, 错位六弯叶桨, 流固耦合, 预应力模态分析

CLC Number:

LUAN Deyu, ZHANG Shengfeng, ZHENG Shenxiao, WEI Xing, WANG Yue. Dynamic characteristics of impeller of perturbed six-bent-bladed turbine in pseudoplastic fluid based on fluid-structure interaction[J]. CIESC Journal, 2017, 68(6): 2328-2335.

栾德玉, 张盛峰, 郑深晓, 魏星, 王越. 基于流固耦合的错位桨搅拌假塑性流体动力学特性[J]. 化工学报, 2017, 68(6): 2328-2335.

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