Entrance analysis of turbulent flow in an array of heated rectangular blocks

A numerical study is conducted to investigate the entrance behavior of turbulent flow over arrays of rectangular heated blocks. The problem formulation is three dimensional and the solution domain includes both the developing and fully developed regions of the array. The blocks are deployed along the lower wall of a parallel-plate duct in an attempt to simulate the cooling passages of electronics equipment, The standard k-ε turbulence model was applied to the developing region of the flow at high Reynolds numbers, while a modified Lam-Bremhorst turbulence model was considered at low Reynolds numbers. The computations are performed for two conventional thermal boundary conditions, namely constant heat flux and constant wall temperature. Reynolds numbers ranged from 10² to 10⁵, with the Prandtl number being equal to 0.7. The array geometry was identified with H/L=1/8, S/L=1/8, B/L=1/2 and the entrance length, I/L=1/2, 2, and 6. To evaluate the accuracy of the turbulence models, numerical solutions were compared with experiment