Developing laminar flow and heat transfer in annular-sector ducts

For annular-sector ducts, steady, laminar, and constant-property forced-con vection flow and heat transfer in the entrance region have been analyzed nu merically using a general, marching procedure. Two types of thermal boundar y conditions have been considered: (1) uniform temperature both axially and peripherally (T boundary condition); (2) uniform axial heat flux with unif orm peripherally temperature at any cross section (H1 boundary condition). Numerical analysis has been conducted in the following range of parameters: D-i/D-o = 0.00, 0.25, 0.50, apex angle of the sector 2 alpha = 18 degrees, 20 degrees, 24 degrees, 30 degrees, 40 degrees, and Pr = 0.707. The soluti ons of the developing Nusselt number and friction factor are presented as f unctions of nondimensional axial distance. Comparisons are made between the computed results and the analytical or numerical results available in the literature. For all cases compared, satisfactory agreement is obtained.