Numerical analysis of laminar heat transfer in entrance region of a horizontal channel with transverse fins

In the present work, a numerical investigation of the laminar fluid flow and heat transfer in the entrance region of a two dimensional horizontal channel, with in-line ribs, is carried out. The computations are based on the Finite Volume method and the SIMPLE algorithm has been implemented. Both sides of the channel are assumed at a constant temperature and physical properties of the fluid are assumed as constant. Computations are performed for the Reynolds number in the range of 100 to 500, Prandtl number of 0.7 and blockage ratio of 0.1, 0.2 and 0.3. The present results show that the ribs interrupt the boundary layers. Flow detaches from the channel wall and it forms a recirculation zone in front of the rib. The reattachment point has the maximum local Nusselt number. The precise location of periodically fully developed region depends on the Reynolds number from the third to the sixth rib. Increasing the rib pitch causes a marginal increase in the local Nusselt number and a decrease in the friction factor. Increasing the blockage ratio results in a moderate decrease in the local Nusselt number.