Three-Dimensional Numerical Analysis of Mixed Convective Heat Transfer in a Horizontal Square Channel with Heated and Cooled Side Walls.

Abstract

Three-dimensional elliptic simulations were carried out to study mixed-convection heat transfer in a horizontal square channel with heated and cooled side walls. Governing equations were solved for Re=100, Pγ=0.72 and Gγ/Re2=0∼50 by the SMIPLE method. Three-dimensional spiral flows were observed along the longitudinal direction of the channel. Secondary flow caused by buoyancy force gave rise to flow reversal at the thermally developing region. The flow reversal regions generated by secondary flow near the upper and lower walls partially prevented the main flow. This flow situation could be considered a fundamental phenomenon for mixed convection at the thermally developing region of the horizontal square channel. The effects of Gγ/Re2 on the local heat transfer and the intensity of secondary flow were also discussed.