Numerical study of convective heat transfer from an array of parallel bluff plates

The turbulent fluid flow and heat transfer characteristics of heated rectangular plates such as fins mounted over a surface are investigated by numerical simulation using a finite-volume method. The investigation is performed taking into account effects of variation of the fin blockage ratio and flow Reynolds number. These parameters were changed to find their effects on reattachment position, velocity vector field, pressure distribution, friction coefficient and overall Nusselt number along the block surfaces. The governing equations are the continuity, momentum and energy equations with RNG based k-ε turbulence model. The temperature field in the block's mantle and on its outer surface was obtained solving the Fourier's conduction equation. Numerical validation is made by comparing the results with experimental measurements and good agreement was observed. Variation of average convection heat transfer coefficient over the block surfaces is identified and a correlation of the form Nu=0.126Re0.68(1+2.13Br) for average overall heat transfer coefficient from the blocks is presented. Considering these blocks to act as fins, a correlation for overall fin efficiency as ηf=2.823Re−0.14Br−0.0526 is also developed.