Electrohydrodynamic instability in a thin fluid layer between parallel plates with electrical conductivity and thermal gradients

• Main Authors: Sen-Tsun Chang, 張森圳
• Other Authors: Falin, Chen
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/27022750048666174759

碩士 === 國立臺灣大學 === 應用力學研究所 === 96 === The onset of electro-hydrodynamic instability within two parallel plates with electrical conductivity and thermal gradients has been concerned in this study by using numerical method. Electrical conductivity depends on local ion concentration and temperature; density depends on local temperature only since the solution is diluted. The temperature profile is governed by temperature difference between two plates and internal heating. Concentration distribution has been quiescent assumed. Applying perturbation method and linear stability analysis, the stability equations can be found. The neutral stability curves are calculated by shooting method with rigid-rigid boundary conditions. The numerical results show that: without internal heating, the flow field becomes more stable when upper plate has been heated. Conversely, the hotter lower plate destabilizes the field and can be reduced to “Rayleigh-Benard convection” problem accurately. While internal heating has been concerned, the temperature profile separates the system into two parts. The upper region is mainly governed by thermal unstable mechanism. The lower region becomes unstable while electro-hydrodynamic overcomes viscous and thermal stable effect.