Flow and heat transfer in a pipe containing a coaxially-rotating disk

Abstract

A numerical investigation was made of steady laminar flow and convective heat transfer in a pipe constricted by a coaxially rotating disk. The analysis was executed by using the finite volume approach. Calculations were made for the through-flow Reynolds numbers (based on the pipe radius) of 10, 25, 50, 75, 100, 125, 150, the rotational Reynolds numbers of 0, 250, 500 and 1000, for the disk-to-pipe radius ratios of 0.9, 0.95 and 0.99, and for the Prandtl numbers of 0.7 and 7. The heat transfer rate, the pressure drop coefficient, and the temperature distributions are determined. The results show that the temperature and flow characteristics are substantially affected by the rotation of the disk. In the disk downstream-flow the wall and disk recirculation zones are noticed. The swirl imparted to the flow measurably increases the heat transfer rate. The increase is especially noticeable when the wall recirculation region does not exist. Physical rationalizations are made of the computed flow features, and a brief description is given of the Nusselt number distribution. (C) 2000 The Japan Society of Fluid Mechanics and Elsevier Science B.V. All rights reserved.