An Equation for Laminar Flow Heat Transfer for Constant Heat Flux Boundary Condition in Ducts of Arbitrary Cross-Sectional Area

Abstract

We can calculate the heat transfer in ducts of arbitrary cross section with the definition of the equivalent diameter only in turbulent flow. In laminar flow, it is not sufficient to define an equivalent diameter, because the boundary layer of each wall is influenced by another wall. Therefore, one needs additional quantities to describe the heat transfer and pressure drop. This is shown for pressure drop calculations by Yilmaz and heat transfer for constant wall temperature by Yilmaz and Cihan. In these works, by using other quantities, it was possible to obtain general equations for pressure drop and heat transfer for constant wall temperature. In the present work, an equation for heat transfer for the boundary condition of constant heat flux at the wall for laminar developed flow in ducts of arbitrary cross-sectional area is given. 14 refs., 1 fig., 4 tabs.