Effects of an inserted square cylinder on wall heat transfer in laminar channel flows

Effects of unsteady flows past a confined square cylinder on wall heat transfer are investigated numerically. Two Reynolds numbers and several the gap distances of the square cylinder are considered to analyze the geometric effects on the wall heat transfer. The results show the detailed description of flow structure and attendant heat transfer caused by the variation of the gap distance. As the gap distance increases, the flow changes from steady asymmetric flow to symmetric vortex shedding having the inversion of the Karman vortex street. Also, the square cylinder induces intensive flow instabilities and significant alteration of the thermal boundary layer. As a result, the temperature distributions on the channel walls become steeper and wall heat transfer is increased.