Numerical simulation of forced convective heat transfer in inclined elliptic ducts with multiple internal longitudinal fins

The paper presents numerical study of forced convective heat transfer in internally finned elliptic geometry to determine the effect of parameters such as Reynolds number, Prandtl number, aspect ratio, fin heights, number of fins and orientations of the duct on the heat transfer coefficient, temperature history and velocity profiles. The walls were assumed to be subjected to a thermal boundary condition of constant heat flux and the effect of slip boundary is assumed negligible. Finite difference technique was adopted for the solution and results were generated using a code written in Qb-64. The study indicated that number of fins (F = 8) provided the optimum heat transfer augmentation. For all the geometries investigated, Nusselt number, average velocity and bulk fluid temperature were enhanced by the inclinations in the range 0 degrees <= theta <= 75 degrees. For a flow regime of 50 <= Re <= 200, the effect of inclination on heat transfer is negligible, but it worth noting the existence of a critical Reynolds number, Re = 200, above which the effect of inclination on fluid flow becomes noticeable. Also, at Pr >= 5, Nusselt number and bulk fluid temperature were independent of fluid properties. The results obtained could be applied in the prediction of parameters for the design of compact heat exchangers for industrial applications. (C) 2017 Faculty of Engineering, Alexandria University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).