Turbulent Heat Transfer in a Channel with a Built-in Square Cylinder: The E ect of Reynolds Number

Turbulent heat transfer, in a three dimensional channel ow, in the presence of a square cylinder, was investigated numerically. The existence of a square cylinder in a channel, compared to a plain one, changes the heat transfer rate from the walls of the channel. A Large Eddy Simulation (LES) of a turbulent ow was performed to simulate ow behavior in a channel for Reynolds numbers in the range of 1000 to 15000. The results obtained for the Nusselt number distribution along the wall of the channel, at Re = 3000, followed those of experimental data with good accuracy. It was observed that the existence of a square cylinder makes the attached wall boundary layer separate, with a subsequent recirculation zone downstream of the cylinder. The Nusselt number distribution along the wall of the channel shows an increase, with a relative maximum, slightly downstream of the reattachment point. Heat transfer from the wall of the channel increases with increasing Reynolds number. A correlation was obtained for the variation of the mean total Nusselt number with the Reynolds number.