Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 0-89116-299-2

International Heat Transfer Conference 7
September, 6-10, 1982, Munich, Germany

COMBINED NATURAL AND FORCED CONVECTION IN VERTICAL DUCTS

Get access (open in a dialog) DOI: 10.1615/IHTC7.2840
pages 419-424

Abstrakt

Numerical solutions to the boundary-layer eguations, expressed in transformed and physical coordinates, are presented for the vertical flow in a duct where thermal wall-boundary conditions lead to aided or opposed natural and forced convection. Results are presented for values of the ratio of (Gr/R2) of 0.001 to 1.0 and for Prandtl numbers of 0.1, 0.72 and 10 and include distributions of pressure drop, wall-shear 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/ R2) leads 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 Reyhner-Flugge-Lotz 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.