Effects of blockage ratio and Prandtl number on steady flow and heat transfer around an inclined square cylinder

چکیده مقاله

Numerical investigation of flow and heat transfer around a long heated inclined square cylinder placed in a horizontal plane channel in a steady laminar regime is carried out for the conditions: 1 ≤ Re ≤ 40, 0.7 ≤ Pr ≤ 100, inclination angle equal to 45° and blockage ratio to β = 1/8, 1/6, and 1/4. The streamlines and isotherms are presented to elucidate the effects of the channel confinement, Prandtl number, and two thermal boundary conditions (constant wall temperature, CWT, and uniform heat flux, UHF) on the physics of the problem. Generally, an increase in a blockage ratio increases the drag coefficient and decreases the wake length. The average Nusselt number also increases with Prandtl and/or Reynolds number. Furthermore, decreasing the blockage ratio decreases the dimensionless local pressure drop and increases the average Nusselt number for low Re and Pr numbers. This can be an economical result for improving the thermal efficiency of the problem. However, for larger Reynolds and Prandtl numbers the average Nusselt number and local pressure drop increase with the blockage ratio. Finally, some simple correlations are introduced for recirculation length, drag coefficient, dimensionless local pressure drop, and average Nusselt number at different blockage ratios.