Flow Structure in an Inner Rotating Annular Channel with Ribbed Wall Cylinder

Le résumé fourni par la source

In this investigation, we explore the flow field of an annular channel between two horizontal concentric rotating cylinders, i.e., between a rotating inner cylinder and a stationary outer cylinder. Resulting from interactions between centrifugal force, viscous force and different boundary conditions, flow fields in an annular channel probably develop groups of opposite Taylor vortices when the Taylor number is higher than a critical value. Geometrical parameters of rotating cylinder channels, such as the channel widths and circumferential ribs are also affected by the flow field. Four types of rotating inner cylinder are available in this experiment: smooth walled (Model A), and circumferential ribs of three different sizes (Models B–D). The aspect ratios for circumferential ribs are 5/3, 5/2, and 10/3, which generate periodically embedded cavities of 10, 15, and 20 mm. The radius ratios between the inner and outer cylinders were ηs=0.89, and ηrib=0.94, respectively. Taylor numbers ranged between (8.565–1312.943)×103, and centrifugal force arising from the rotation of Model A was F s=0.22–3.3 N. The centrifugal forces arising from the inner cylinders with embedded circumferential ribs were F rib=0.23–3.49 Nt. Because the wavelength of the Taylor vortices was subjected to the influence of different geometrical conditions, the flow field structure of Model A was different at both ends of the cylinder. Conversely, various forms of Taylor vortices occurred between annular channels with circumferential ribs in the case of Models B–D, and the vortex evolved from the edge of the circumferential ribs in a more stable manner than in Model A. The wavelengths of the Taylor vortices were λA=30 mm, λB and λD=20 mm, and λC=15 mm. Experimental results of flow visualization demonstrated it to be well suited for benchmarking engineering designs for heat transfer, cooling, and tribology of rotating machinery.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.