Numerical study of turbulent flow and heat transfer from an array of thick plates

Convective heat transfer in turbulent flow from an array of blunt plates is numerically studied. The flow is assumed to be steady, two dimensional, incompressible and turbulent. A modified two equation k-epsilon model with the preferential dissipation modification is incorporated to determine accurately turbulent flow field, as well as the recirculation pattern along the entrance region of the plates. To predict the local variations of turbulence quantities in the k equation, a three-layer, near wall turbulence model was examined based on the wall function. The governing equations are solved using finite volume technique based on the bounded skew hybrid difference scheme BSHD, and the PISO algorithm to iterate for pressure corrections. The solutions were obtained using a two-pass procedure, devised to allow for the correct use of the wall functions. Computations for Re-D, were obtained in the range 2.5.10(4) to 10(6): Prandtl numbers of 1, 2, 5, and 10 and blockage ratios of 5 % through 30 %. Results of friction coefficient, and Nusselt number distribution for the combined entry length problem are presented for different flow conditions and plates thickness. These findings are in accord with previously published experimental and theoretical results of a single plate. (C) 2000 Editions scientifiques et medicales Elsevier SAS.