Numerical Analysis of Bubble Growth under Electric Field.

Abstract

Numerical analysis has been performed on bubble growth and deformation under an electric field in order to elucidate the mechanisms of boiling heat transfer enhancement by EHD (Electro- Hydrodynamic) effects. Transient Navier-Stokes and Maxwell's equations were solved simultaneously for liquid and vapor phases in a two-dimensional cylindrical co-ordinate system making use of the VOF (Volume of Fluid) method. Bubble growth in liquid R113 under atmospheric pressure has been simulated. First, elongation of a single bubble under uniform electric field is simulated and the final shapes of the bubble are found to be in good agreement with Garton's analytical and experimental results. Second, the bubble deformation process under non-uniform electric field was simulated. A bubble initially attached to the lower electrode starts to deform and finally detaches from the lower electrode. The shape of bubble depends on the intensity of the electric field. The behavior of bubbles, the velocity vectors, and the contours of electric field are also shown and compared with experiment.