Effect of radial electric field on heat and momentum transfers in dielectric organic liquid for laminar flow through concentric annuli

Abstract Experiments were conducted to investigate changes in convective heat transfer in flows of dielectric organic liquids in annuli between copper tube and concentric wires. Also investigated was longitudinal pressure drop in the flow which could be induced by applying electric fields of direct current between the wall of the tube and the central wire electrode. In the laminar range of Reynolds number, heat transfer rates at the outer wall increased in the thermally well-developed region, and the thermal development was advanced. On the other hand, pressure drops were also increased in liquids of small Prandtl number. In the transitional and turbulent range, however, neither changes of heat nor momentum transfer were noticeable. To express these results in the low Reynolds number range a semi-empirical formulation in non-dimensional terms was derived from the similarity principle.