Computational analysis of heat transfer and fluid flow characteristics over flat bars of different heights

Menni, Y.; Azzi, A.; Zidani, C.

Rеvuе des Energies Renouvelables
Volume 19, Numéro 3, Pages 345-366
2016-09-30

Computational Analysis Of Heat Transfer And Fluid Flow Characteristics Over Flat Bars Of Different Heights

Authors : Menni Y. . Azzi A. . Zidani C. .

Abstract

A computational analysis of steady state turbulent forced convection flow in a two-dimensional isothermal-wall rectangular channel provided by detached solid flat bars with the same cross-sectional areas in a tandem arrangement is carried out in the present work. The fluid (air) is considered, Newtonian, incompressible with constant properties. The Reynolds number based on the hydraulic diameter of the channel is varied between 10.000 and 25.000. The governing equations are solved by the Finite Volumes Method and the Simplec-algorithm, in two dimensions, employing the Commercial CFD software Fluent 6.3 with the k- standard model to describe the turbulence. In particular, fields and profiles of axial velocity, local and average heat transfer coefficients as well as pressure loss were examined along the channel at constant wall temperature condition along the top and bottom walls. The parameters of the numerical study are the Reynolds number and the flat bar size. The results reveal essentially, that the size of the bars can alter substantially the airflow and convective heat transfer characteristics. The numerical data indicates that an increase in the bar height causes a substantial increase in the Nusselt number but the pressure loss is very significant for all Reynolds numbers used.