Electrohydrodynamically-Enhanced Forced Convection in a Horizontal Channel with Oscillatory Flows

Abstract

Prior studies on electrohydrodynamically enhanced forced convection in a horizontal channel have revealed the existence of oscillatory flows. These oscillatory flows are the product of interactions between the electric body force and flow inertia of the primary flow. It has also been shown that heat transfer can be significantly enhanced when operating in this oscillatory flow mode. It is speculated that heat transfer may be further enhanced by exciting the primary flow in a frequency similar to those observed for the oscillatory flows (i.e., the so-called resonant effect). To verify this speculation, computations have been performed for primary flows excited with a frequency that is either a fraction or multiple of the natural frequency observed in the original oscillatory flows. The results show that an inlet flow excited at the natural frequencies produces the best heat transfer enhancement in the single-cell regime, and the enhancement increases with the Reynolds number. However, the results show an opposite trend in the multiple-cells regime.