Combined free and forced convection laminar film condensation on an inclined circular tube with isothermal surface

Laminar film condensation on an inclined circular tube, under the condition of combined free and forced convection, is analyzed. The assumptions are a s in the analysis of Shekriladze and Gomelauri [Theoretical study of lamina r film condensation of flowing vapour, Int. J. Heat Mass Transfer 9 (1966) 581-591]. In addition, some approximations are introduced for the determina tion of the interfacial shear stress. The resultant governing equation, in special cases, yields the known analytical solutions of horizontal and vert ical tubes, which were obtained in previous studies. A numerically obtained solution reveals the effects of vapour velocity and gravity forces on loca l and mean Nusselt numbers. For the case of an inclined tube with infinite length, an explicit simple expression has been obtained, based on numerical results, to calculate the mean Nusselt number for the whole tube surface. (C) 1999 Elsevier Science Ltd. All rights reserved.