ISSN Online: 2377-424X
ISBN Print: 0-85295-345-3
International Heat Transfer Conference 10
ANALYSIS OF COMBINED FORCED AND FREE LAMINAR CONVECTION IN THE ENTRANCE REGION OF AN INCLINED HEATED CIRCULAR TUBE
Résumé
A numerical investigation has been conducted to study the effects of natural convection on the developing laminar flow in horizontal and inclined tubes subject to a uniform wall heat flux. Typical results obtained for air and Gr = 105 clearly show that the primary flow and thermal fields are significantly disturbed under natural convection effects manifested by two symmetrical vortices which persist throughout the tube length. The primary flow is no longer axisymmetrical and isotherms are drastically distorted. The phenomenon of bifurcation has also been observed for the case of fully-developed flow. Dual solutions showing the "two-vortices" and "four-vortices" structures of the secondary flow have been found at high Grashof number.