Fluid Flow anf Heat Transfer Characteristics for Arrays of Heated Blocks

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The flow visualization was done for low Reynolds number fluid flow in an array of the heated square blocks deployed along one wall of the parallel plates duct. This configuration simulates the forced-convection cooling of printed circuit boards encountered in large scale integrated elements. The pearl graze was used for the flow visualization as a tracer. The geometry of the problem is specified by the block dimension (L), the block thicknes (B) , the inter-block gap (S) and the height of the flow passage between the block and the opposite wall of the duct ( H). The experiments were done for B/L=3/8, S/L=1/4, H/L=1/4 to 5/8. The critical Reynolds numbers obtained from the flow visualization were 1000 to 1500 depending on the height of the duct.Three-dimensional numerical analysis were conducted to obtain the fluid flow and heat transfer characteristics in both th periodic fully developed region and the entrance region of the array of the heated blocks for the range of Reynolds number from 1900 to 5000. Lam and Bremhorst low-Reynolds-number two equation model was used for the turbulent model. The results for the entrance region were compared with the experimental results. The result for the periodic fully developed region was published in the Numerical Heat Transfer and the result for the entrance region was accepted for publication in the same journal.Three-dimensional numerical analysis for the transition region of Reynolds number ranges from 100 to 2500 were conducted with using Lam-Bremhorst low-Reynolds-number two equation turbulence model to obtain the fluid flow and heat transfer characteristics in the transition region. The duct geometries tested were B/L=3/8, S/L=1/4 and H/L=1/4 to 5/8. As a consequence, in the case of H/L=5/8, the transition to the turbulent flow starts from Re=700.