Laminar forced convection heat transfer in rotating rectangular ducts. (1st report. Numerical analysis in the case of positive rotation).

Abstract

Fully developed laminar forced convection heat transfer in curved rectangular ducts rotating at a constant angular velocity about an axis through the center of curvature of ducts is studied. Thermal boundary conditions of fluid flow are assumed to be subject to uniform wall heat flux. Navier-Stokes and energy equations are solved by the finite-difference method for Pr=0.7. The case for the positive rotation of a duct is considered. Velocity and temperature fields are obtained for various rotation rates and Reynolds numbers. A double-vortex secondary flow appears at a low to moderate rotation rate and Re number. It is found that an additional pair of vortices appeared and disappeared for a higher range of Reynolds numbers under the influence of centrifugal and Coriolis forces. The friction factors and Nusselt numbers are also obtained. The numerical results in regard to the friction factors are in good agreement with experimental results obtained by other researchers.