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Acta Aeronautica et Astronautica Sinica ›› 2023, Vol. 44 ›› Issue (18): 128328-128328.

• Fluid Mechanics and Flight Mechanics • Previous Articles     Next Articles

First Hopf bifurcation of conducting fluid in three-dimensional square cavity

Jingkui ZHANG1, Jiapeng CHANG1, Miao CUI2(), Qifen LI1, Hongbo REN1, Yongwen YANG1   

  1. 1.College of Energy and Mechanical Engineering,Shanghai University of Electric Power,Shanghai 200090,China
    2.State Key Laboratory of Structural Analysis,Optimization and CAE Software for Industrial Equipment,Dalian University of Technology,Dalian 116024,China
  • Received:2022-11-28 Revised:2023-01-29 Accepted:2023-03-17 Online:2023-09-25 Published:2023-04-03
  • Contact: Miao CUI E-mail:miaocui@dlut.edu.cn
  • Supported by:
    National Natural Science Foundation of China(12172078)

Abstract:

The unstable transition of conducting fluid caused by Hopf bifurcation under the action of magnetic field has not been studied. In this work, the numerical method SCM-ACM, which combines the spectral collocation method and artificial compressibility method developed by our research group, is used to solve the magnetohydrodynamics (MHD) governing equations under the subcritical flow state directly. The Fourier analysis is employed to calculate the spectral distribution of velocity oscillation. The first Hopf bifurcation of a conducting fluid from a steady state flow to an unsteady periodic oscillatory flow in a three-dimensional square cavity is studied with a range of Hartmann number Ha. The results show that the magnetic field strongly suppresses velocity oscillation and significantly increases the critical Reynolds number Recr for the first Hopf bifurcation. With the increase of Ha from 0 to 5, the decay of velocity amplitude increases sharply in a parabolic form. The Recr also increases in a parabolic form, from 1 916.6 to 2 040.1. However, the velocity oscillations with different Ha only have a unique dominant dimensionless angular frequency (ω=0.575 2). The present research method and results on Hopf bifurcation can provide reference for the engineering design and operation control.

Key words: first Hopf bifurcation, magnetohydrodynamics (MHD), oscillatory flow, instability analysis, spectral collocation method

CLC Number: