Heat transfer enhancement by electrohydrodynamics in wavy channels

Abstract

The present study numerically investigated the heat transfer process occurred in a wavy channel enhanced by electrohydrodynamics (EHD). The mechanisms of the EHD-enhanced heat transfer in wavy channels differ from those in a straight channel. An advantageous position for single electrode is proposed to be above the peak of wave in a continuous wavy channel. Strategies for aligning multielectrodes in the EHD-enhanced continuous or discontinuous wavy channels are proposed based on interpretation on the simulation outcomes for single electrode. The ratio of horizontal section length to wave length (l/λ) significantly affects the heat transfer enhancement, unlike the case in continuous wavy channel (l/λ = 0). The optimal electrode arrangement for continuous wavy channels is inappropriate for discontinuous wavy channels, the electrodes should be placed above the junction of wave and horizontal section. The design criteria are proposed for enhanced heat transfer performance in discontinuous wavy channels with multiple electrodes: the electrode spacing should be as large as possible to minimize the barrier effect when the ratio l/λ < 0.15; however it is beneficial to reduce the electrode spacing when the ratio l/λ > 0.15.