TURBULENT FLOW AND HEAT TRANSFER IN A CHANNEL WITH A SQUARE BAR DETACHED FROM THE WALL

Abstract

Computations are conducted to study the heat transfer and friction in a channel with a mounted square bar of different sizes detached from the channel wall. The Reynolds number (Re) based on channel height ranges from 10 4 to 105, whereas the bar height to channel height (d H) varies from 0.15 to 0.35. The channel walls are subjected to a constant wall temperature. The standard k- epsilon turbulence model and a modified version were used in conjunction with the Reynolds-averaged momentum and energy equations for the simulations and were compared thereafter. A finite volume technique with staggered grids combined with the SIMPLEC algorithm is applied. Results show that the local and global Nusselt numbers on the channel walls are strongly modified by the unsteady vortex shedding induced by the bar. The displacement of the bar from the channel axis toward the wall did not cause an increase in the global heat transfer coefficient on the channel walls compared with the bar centered in the channel.