Pseudo 3D modeling of suction and injection effects on fully developed laminar flow and heat transfer in rectangular fuel cell channels

Abstract

In this paper, the flow in the rectangular fuel cell channel with different aspect ratios has been numerically simulated. The bottom wall of the rectangular channel is porous and subjected to a uniform mass injection or suction, while the other three walls are nonporous or impermeable. Assuming the hydro-dynamically and thermally fully developed flow, the mass, momentum, and energy equations have been solved with a two-dimensional code. The present numerical results are in good agreement with the numerical results in the literature. The wall friction coefficients and Nusselt numbers were obtained for different aspect ratios, different wall Reynolds numbers (for suction and injection), and different thermal boundary conditions. The results show that for each aspect ratio, friction coefficient ( fRe) is larger for injection than for suction. Also at unit expect ratio, a/ b = 1, the fRe have minimum value for each wall Reynolds number ( Rem) and with increasing and decreasing aspect ratio, fRe increases. The changes of Nusselt ( Nu) number with Rem and aspect ratio is dependent on the thermal boundary conditions and definition of Nu number (for combined boundary condition).