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过程工程学报 ›› 2020, Vol. 20 ›› Issue (12): 1424-1431.DOI: 10.12034/j.issn.1009-606X.220015

• 流动与传递 • 上一篇    下一篇

基于流固耦合的斜轴式搅拌器水力性能数值分析

黎义斌1*, 梁开一1, 李正贵2   

  1. 1. 兰州理工大学能源与动力工程学院,甘肃 兰州 730050 2. 西华大学流体及动力机械教育部重点实验室,四川 成都 610039
  • 收稿日期:2020-01-08 修回日期:2020-03-18 出版日期:2020-12-22 发布日期:2020-12-22
  • 通讯作者: 黎义斌
  • 基金资助:
    教育部重点实验室开放基金

Numerical analysis of hydraulic performance of tilted shaft agitator based on fluid-structure interaction

Yibin LI1*, Kaiyi LIANG1, Zhenggui LI2   

  1. 1. School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China 2. Key Laboratory of Fluid and Power Machinery, Ministry of Education, Xihua University, Chengdu, Sichuan 610039, China
  • Received:2020-01-08 Revised:2020-03-18 Online:2020-12-22 Published:2020-12-22
  • Supported by:
    Financial supports from Key laboratory opening fund of Ministry of Education

摘要: 为研究气液两相搅拌器的剪切分散性能,提出了一种上层为六直叶圆盘涡轮,下层为推进式桨叶的双层搅拌器,建立0°~30°倾斜轴搅拌器的模型,基于雷诺时均N-S方程、RNG k??湍流模型和VOF多相流模型,研究了倾斜角对斜轴式搅拌器内部搅拌性能的影响,基于流固耦合方法对斜轴式搅拌器进行了应力计算和失效分析。结果表明,倾斜轴改善了搅拌器内的轴向流动,气相沿轴向的扩散能力增强;倾斜角介于0°~30°时,搅拌器达到95%含气率的时间比0°时有明显缩短,25°和30°倾斜轴搅拌器所需时间相较0°分别缩短12.50%和22.71%;在相同转速下,轴功率随轴倾斜角度增大而增大;转速越高,搅拌器达到理想含气率的时间越短,且不同转速下混合时间随轴倾斜角度的变化规律基本一致;随倾斜角度增大,搅拌器所受等效压力随之增大,倾斜角度为30°时直叶圆盘涡轮危险断面处应力比桨叶许用扭转应力高8.7%,超出安全应力范围,桨叶易出现断裂失效问题。

关键词: 倾斜轴, 气液两相流, 流固耦合, 搅拌器

Abstract: In order to reveal the shear-dispersion performance of gas?liquid two-phase agitator, a double-layer agitator with six flat blade disk turbine on the upper layer and propeller blade on the lower layer was proposed and models of tilted shaft agitators with different angles (0°~30°) were established. Calculation and analysis of the hydraulic performance in a stirred tank were carried out by Reynolds average Navier-Stokes equation, RNG k?? turbulence model and VOF multiphase flow model. Unidirectional fluid-structure interaction was used to analyze the stress magnitude and distribution characteristics of tilted shaft agitator, and the material failure was checked based on the ANSYS Workbench platform. It was concluded that the inclined shaft improved the axial flow in the agitator, and the gas phase diffusion ability in the axial direction was enhanced; when the inclination angle was between 0°~30°, the time for the agitator to reach 95% gas content was significantly shorter than that at 0°, and the time required for 25° and 30° tilting shaft stirrers were shortened by 12.50% and 22.71%. At the same rotating speed, the shaft power increased with the increase of shaft tilt angle. The higher the rotation speed, the shorter the time for the agitator to reach the ideal gas content. The variation law of the mixing time with the shaft tilt angle under different rotation speeds was basically consistent. As the inclination angle increased, the equivalent stress and shaft power of the agitator increased. When the inclination angle was 30°, the stress at the dangerous section of the flat disk turbine agitator exceeded the range of safety stress, which was prone to fracture failure. When the inclination angle was 30°, the stress at the dangerous section of the straight blade disc turbine was higher than the allowable torsional stress of the blade by 8.7% which was beyond the safe stress range, and the blade was prone to fracture failure.

Key words: tilting shaft, gas-liquid two-phase flow, fluid-structure interaction, agitator