Effects of wall and non-uniform thermal condition on developing flow with mixed convection in an inclined tube

The developing flow with mixed laminar convection in an inclined tube has b een studied numerically for four different thermal boundary conditions: a u niform heat flux is applied over the entire circumference or its top half a t either the outer tube surface or the fluid-solid interface. The calculate d results for local parameters (circumferential distribution of the interfa cial temperature, axial velocity profile, etc.) and for average variables ( circumferentially average values of the Nusselt number and of the Interfaci al shear stress) are quite different, especially for high values of Grashof number. Thus, for Gr = 10(6), Re = 500 and Pr = 7, the asymptotic average Nusselt number for a uniform heat flux applied over the entire outer tube s urface is 16.47; the corresponding values for a heat flux applied on the fl uid-solid interface is 26.14 for uniform flux over the entire circumference and 29.71 for a hear flux applied only on the top half of the interface. ( C) Elsevier Press.