Flow through Ribbed Annuli
Abstract
Flows in circular annuli with surface grooves are studied. Analysis is focused of two-dimensional grooves with an arbitrary shape and utilizes numerical simulations based on spectral discretization. Effects of boundary shape are modeled using Immersed Boundary Conditions as well as Domain Transformation Methods. Results for two extreme orientations of the grooves, i.e., grooves being parallel and transverse to the axis, are discussed. It is shown that low-order models of surface topography provide a very accurate prediction of pressure losses as long as grooves' amplitude remains small. Changes of pressure loss can be divided into those associated with changes of the average position and shape of the grooves. It is shown that curvature effects are important as long as the radius of the inner cylinder does not exceeds ten annuli's openings. Analytical solutions are possible for small wave number limits. Flow lift up is observed in the large wave number limit.
- Publication:
-
APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 2011
- Bibcode:
- 2011APS..DFDE17006M