Unsteady Heat Transfer and Pressure Drop in Channels with Obtacles Mounted on the Upper and Lower Walls

ABSTRACT

A numerical study is performed to investigate heat transfer and pressure drop in a rectangular channel with alternating heated obstacles mounted on both upper and lower walls. Time-dependent two-dimensional laminar flow with constant thermophysical properties is assumed for air and Reynolds number ranging from 100 to 1,000. A detailed analysis is carried out to investigate flow pattern, Nusselt number, and friction factor for various obstacle height, width, and spacing. The results show a transition to unsteady flow at a moderate value of the Reynolds number. For the unsteady case, the flow becomes periodic in time with vortex-shedding oscillations.