CONFINE► FLOW AND HEAT TRANSFER ACROSS A TRIANGULAR CYLINDER IN A CHANNEL

Abstract

This paper describes the effects of blockage ratios on the fluid flow and heat transfer across a long equilateral triangular cylinder placed in a horizontal channel for Reynolds numbers range 1 -80 and blockage ratios of 0.1, 0.125, and 0.25 for the fixed Prandtl number of 0.71. The governing Navier-Stokes and energy equations along with appropriate boundary conditions are solved by using a commercial CFD solver FLUENT (6.3). The computational grid is created in a commercial grid generator GAMBIT. The computed flow and temperature fields were demonstrated in the form of stream-lines and isotherms, respectively. The engineering parameters such as mean drag coefficient, wake/recirculation length, average Nusselt number, and Strouhal number, etc. are calculated for the above range of conditions studied here. The mean drag coefficient and average Nusselt number are found to increase with an increase in the blockage ratio for a fixed value of Reynolds number in the steady regime. However, for a fixed value of Reynolds number, wake length is decreasing with increasing value of blockage ratio in the steady regime. The critical value of the Reynolds number (i.e., transition to transient) is found to be increasing with increasing in the value of blockage ratio. Finally, simple correlations for wake length, mean drag coefficient and average Nusselt number are obtained for the range of conditions covered here.