Laminar Heat Transfer and Pressure Drop in a Rectangular Duct Rotating About a Parallel Axis

Abstract

Experimental results were obtained on pressure drop and heat transfer in a laminar flow of air in a rotating heated rectangular duct. The duct had a 2 to 1 aspect ratio, and was parallel to, but displaced from, the rotor axis. Data presented on Nusselt number in the inlet region and dimensionless pressure drop in the inlet and fully developed regions were found to be in close agreement with numerical finite difference solutions to the laminar flow equations. Laminar heat transfer and pressure drop are strongly affected by rotation, beginning to increase for values of Grashof number in excess of 103. For a Grashof number of 106, the Nusselt number is approximately twice the value of that in a flow with zero Grashof number. The effect of rotation on dimensionless pressure drop is smaller, with increases of the order of 35 percent occurring from Gr = 0 to 106.