Forced convection heat transfer from two heated blocks in pulsating channel flow

Abstract

The pulsating flow and attendant heat transfer characteristics from two heated blocks in a channel have been numerically investigated. At the channel inlet, a pulsating flow U-i, i.e. U-i= U-o(1 + A sin omega tau), is imposed with uniform temperature T-c. The block surfaces in the channel are at constant temperature T-H. The channel walls are assumed to be adiabatic. Comprehensive time-dependent flow and temperature data are obtained and averaged over a cycle of pulsation in a periodic steady state. The effects of the important governing parameters, such as Reynolds number, Re, Strouhal number, St, pulsation amplitude, A, and the spacing between two blocks, w/H, on the heat transfer rate from the heated blocks and the flow behavior in the vicinity of the blocks are also investigated in detail. The results obtained indicate that the recirculation flows behind the downstream block as well as inside the inter-block region are substantially affected by Strouhal number Sr and inter-block spacing w/H. This, in turn, has a strong influence on the thermal transport from the heated blocks to the pulsating flow. The present results are also compared with those obtained for a steady non-pulsating flow, and the effect of pulsation on the transport process is scrutinized. (C) 1997 Elsevier Science Ltd.