ISSN Online: 2377-424X
ISBN Print: 0-89116-559-2
International Heat Transfer Conference 8
DERIVATION OF THE SKIN FRICTION AND HEAT TRANSFER LAWS FOR TURBULENT TWO-COMPONENT BUBBLY FLOWS IN PIPES
Résumé
The skin friction and heat transfer laws for turbulent two-component bubbly flows in pipes are obtained under the following conditions. The flow is assumed to be vertical, steady, fully developed and to circulate in the upward direction. The main arguments used in this work are : first the subsistence at low values of the void fraction of the logarithmic velocity and temperature profiles near the wall ; secondly the similarity of the modifications caused by the bubbles on these profiles and those created by a grid in a single-phase turbulent boundary layer. The form of the friction and heat transfer laws derived is in principle valid when the void fraction remains inferior to 0.10. However comparisons with the local measurements presently available in this field show that the effective range of validity is О < α < o.3, which corresponds to the whole bubbly flow pattern.