A temperature wall function for turbulent mixed convection from vertical, parallel plate channels

Abstract

Despite tremendous increase in computing power and an attendant increase in direct numerical simulations (DNS) of turbulent flows, near wall treatment continues to be the mainstay of most commercial packages as well as in house codes, for wall bounded turbulent flows. Even so efficient near wall treatments of truly “mixed convection flows” are not many in the open literature. This paper looks at a possible approach to the treatment of a typical mixed convection problem from vertical, parallel plate channels. The procedure employed is an asymptotic blending of natural and forced convection wall functions, which themselves are derived based on an asymptotic analysis of flow in the near wall region. Testing of the wall function was done for both aiding and opposing flows with DNS data available in literature.