Enhancement of convection heat transfer using EHD conduction method

Laminar forced convection heat transfer in an annulus is enhanced using electrohydrodynamics (EHD) technique. A novel EHD-enhanced double pipe heat exchanger is designed and incorporated with six pairs of electrodes. An experimental setup is constructed to investigate heat transfer enhancement, pressure drop and power consumption in the double pipe. The finite volume method is employed to solve the governing equations of EHD conduction pumping, Navier-Stokes and energy. The numerical results are in agreement with the experimental results and demonstrated that in the considered range of the parameters, heat transfer enhances up to 50% with low electric power consumption and the method is more effective in lower Reynolds numbers. An effectiveness parameter is introduced which considers both heat transfer enhancement and pumping power consumption. Increasing applied voltage will improve performance until an optimum voltage which generates a cross-stream flow comparable to main-stream inlet flow. The flow patterns of the induced cross-stream flow are investigated using numerical simulation.