Thermo-electro-hydrodynamic instabilities in a dielectric liquid under microgravity

Paper number

IAC-11,A2,2,11,x11901

Author

Prof. Innocent Mutabazi, Université du Havre, France

Coauthor

Dr. Satish Malik, University of Le Havre, France

Coauthor

Dr. Olivier Crrumeyrolle, France

Year

2011

Abstract

We present recent results on the stability of a dielectric liquid in a cylindrical annulus with a coupled action of a radial alternating high voltage and a radial temperature gradient in  microgravity conditions. The vorticity equation of such a flow exhibits a baroclinic force term that involves an electric gravity which decreases with the radial distance. This gravity is responsible of the buoyancy force (electric Archimedial force) under microgravity [1-3]. The problem of the thermal convection induced by electric gravity is investigated through linear stability analysis for an infitely long annulus and through direct numerical simulation for a finite-length annulus. We have determined critical parameters (electric Grashof number, wavenumber, frequency) as functions of electric voltage and temperature gradient. In particular, we have found that, for a finite length annulus, critical modes correspond to vortices aligned in the azimuthal direction (columns). We have computed the heat transfer for different values of temperature gradient and of the electrical voltage. 
Numerical results are compared with preliminary results of a parabolic flight experiment. These results are complementary to those available up to now in the literature[1-3].
[1]B. Chandra and D.E. Smylie, Geophys. Fluid Dyn. 3, 211(1972)
[2]M. Takashima, Q.J. Mech. Appl. Math. 33, 93(1980)
[3]M. Smieszek, O. Crumeyrolle, I. Mutabazi, C. Egbers, IAC-08-A2.2.9, Glasgow (2008).

Abstract document

IAC-11,A2,2,11,x11901.brief.pdf

Manuscript document

IAC-11,A2,2,11,x11901.pdf (🔒 authorized access only).

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