Combined natural and forced convection in vertical ducts
Abstract
Numerical solutions to the boundarylayer equations, expressed in transformed and physical coordinates, are presented for the vertical flow in a duct where thermal wallboundary conditions lead to aided or opposed natural and forced convection. Results are presented for values of the ratio of (Gr/Rsquared) of 0.001 to 1.0 and for Prandtl numbers of 0.1, 0.72, and 10 and include distributions of pressure drop, wallshear parameter, Nusselt number and nondimensional velocity and temperature. The results for the aided and opposed situations are compared and particular attention is focused on the opposed situation where increasing values of (Gr/Rsquared) lead to flow separation and to the movement of the location of the separation towards the leading edge. The numerical scheme, using an inverse boundary method with the ReyhnerFluggeLotz assumption, allowed the calculation to proceed smoothly from the attached to separated flow and, for example, determined the low values of Nusselt number which occur in the separated region.
 Publication:

Heat Transfer 1982, Volume 3
 Pub Date:
 1982
 Bibcode:
 1982hetr....3..419C
 Keywords:

 Computational Fluid Dynamics;
 Ducted Flow;
 Forced Convection;
 Free Convection;
 Thermal Boundary Layer;
 Finite Difference Theory;
 Nusselt Number;
 Vertical Orientation;
 Wall Temperature;
 Fluid Mechanics and Heat Transfer