CONVECTIVE SPECIFIC-HEAT TRANSFER IN LIQUIDS IN THE PRESENCE OF NONUNIFORM ELECTRIC-FIELD

The electroconvective specific-heat transfer coefficient has been meas ured in various liquids (methanol, kerosene, silicon oil and ethanol) from a single platinum wire (diameter = 0.025 mm) mounted along the ax is of a copper cylinder (diameter = 53 mm). The heat transfer coeffici ent has been evaluated under the influence of a.c. and d.c. fields. An a.c. field always causes an enhancement in the heat transfer coeffici ent. A d.c. field causes an inhibition in heat transfer in methanol. A similar trend is noticed in kerosene, but the heat transfer coefficie nt increases again as the field is increased. An enhancement in the he at transfer coefficient is observed in silicon oil, and a similar tren d is noticed in ethanol, but the heat transfer coefficient decreases a gain as the field is increased. The effect of cylinder orientation on convection is studied. The efficiency of convection has been calculate d for various liquids using an empirical relation. The efficiency obta ined in a d.c. field is found to be higher than in the a.c. field. A s imilar trend is also noticed for the electric Nusselt number.