Flow past rotating cylinders: Effect of eccentricity

Authors
Citation
S. Mittal, Flow past rotating cylinders: Effect of eccentricity, J APPL MECH, 68(4), 2001, pp. 543-552
Citations number
15
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Mechanical Engineering
Journal title
JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME
ISSN journal
0021-8936 → ACNP
Volume
68
Issue
4
Year of publication
2001
Pages
543 - 552
Database
ISI
SICI code
0021-8936(200107)68:4<543:FPRCEO>2.0.ZU;2-U
Abstract
Computational results are presented for flows past a translating and rotati ng circular cylinder. A stabilized finite element method is utilized to sol ve the incompressible Navier-Stokes equations in the primitive variables fo rmulation. To validate the formulation and its implementation certain cases , for which the flow visualization and computational results have been repo rted by other researchers, are computed. Results are presented for Re=5, 20 0 and 3800 and rotation rate, (ratio of surface speed of cylinder to the fr eestream speed of flow), of 5. For all these cases the flow reaches a stead y state. The values of lift coefficient observed for these flows exceed the limit on the maximum value of lift coefficient suggested by Goldstein base d on intuitive arguments by Prandtl. These observations are in line with me asurements reported, earlier by other researchers via laboratory experiment s. To investigate the stability of the computed steady-state solution, rece ptivity studies involving an eccentrically rotating cylinder are carried ou t. Computations are presented for flow past a rotating cylinder with wobble ; the center of rotation of the cylinder does not match its geometric cente r These computations are also important from the point of view that in a re al situation it is almost certain that the rotating cylinder will be associ ated with a certain degree of wobble. In such cases the flow is unsteady an d reaches a temporally periodic state. However the mean values of the aerod ynamic coefficients and the basic flow structure are still quite comparable to the case without any wobble. In this sense, it is found that the two-di mensional solution is stable to purely two-dimensional disturbances.