Numerical simulation of electrohydrodynamically enhanced natural convection heat transfer of dielectric liquid in a horizontal annulus

摘要

The electrohydrodynamically enhanced natural convection of dielectric liquids in a horizontally cylindrical annulus was numerically investigated under DC and pulsed applied electric field conditions over the range of Rayleigh number from 10/sup 4/ to 2*10/sup 4/, the Prandtl number from 5 to 7, and the electric Rayleigh number from 0 to 2*10/sup 3/ for the inner-to-outer radius ratio of 2. Simulation results show that the applied, radial, DC electric field always enhances the heat transfer by natural convection process. The velocity and heat transfer enhancement are from a factor of 2 to 20 and from 10% to 30%, respectively, for EI varying from 5*10/sup 2/ to 2*10/sup 3/.