Effect of Channel Orientation of Local Heat (Mass) Transfer Distributions in a Rotating Two-Pass Square Channel With Smooth Walls

Abstract

Naphthalene sublimation experiments have been conducted to study the effects of channel orientation, rotational Coriolis force, and a sharp turn, on the local heat (mass) transfer distributions in a two-pass square channel with a sharp turn and smooth walls, rotating about a perpendicular axis. The test channel was oriented so that the direction of rotation was perpendicular to or at a 45 deg angle to the leading and trailing walls. The Reynolds number was kept at 5,500 and the rotation number ranged up to 0.24. For the radial outward flow in the first straight pass of the diagonally oriented channel, rotation-induced Coriolis force caused large monotonic spanwise variations of the local mass transfer on both the leading and trailing walls, with the largest mass transfer along the outer edges of both walls. Rotation did not lower the spanwise average mass transfer on the leading wall and did not increase that on the trailing wall in the diagonally oriented channel as much as in the normally oriented channel. The combined effect of the channel orientation, rotation, and the sharp turn caused large variations of the local mass transfer distributions on the walls at the sharp turn and immediately downstream of the sharp turn. The velocity fields that were obtained with a finite difference control-volume-based computer program helped explain how rotation and channel orientation affected the local mass transfer distributions in the rotating two-pass channel.

Heat (Mass) Transfer Distributions in a RotatingTwo‐Pass Channel with Angled Ribs

“…8 and 9 are quite similar to those in channels with all smooth walls and with transverse ribs in the first pass only (Park, 1996). With increasing rotation number, the mass transfer along the outer edges of the leading wall in the turn increases significantly.…”

“…Increasing the rotational speed causes larger velocity and concentration gradients near the trailing wall and smaller gradients near the leading wall, increasing the difference between the mass transfer on the two walls. (Park, 1996).…”

Flow structure, heat transfer and pressure drop in varying aspect ratio two-pass rectangular smooth channels

“…It was found that the sharp turn enhances the heat transfer but with large friction losses. The effect of sharp turning flows in a two-pass square channel with smooth walls using the naphthalene mass transfer technique was reported by Park et al [15]. They found very large spanwise variation in mass (heat) transfer at the turn and upstream of the outlet pass.…”

Mass Transfer Effects on Stokes Problem for an Infinite Vertical Plate in a Rotating Fluid.

“…Mass transfer processes abound in the world around. Park and Lau [9] ) and Park et.al. [10] Study the effect of rotational Coriolis force experimentally on mass transfer distribution.…”