Flow regimes in a plane Couette flow with system rotation
2010 (English)In: Journal of Fluid Mechanics, ISSN 0022-1120, E-ISSN 1469-7645, Vol. 648, 5-33 p.Article in journal (Refereed) Published
Flow states in plane Couette flow in a spanwise rotating frame of reference have been mapped experimentally in the parameter space spanned by the Reynolds number and rotation rate. Depending on the direction of rotation, the flow is either stabilized or destabilized. The experiments were made through flow visualization in a Couette flow apparatus mounted on a rotating table, where reflected flakes are mixed with the water to visualize the flow. Both short- and long-time exposures have been used: the short-time exposure gives an instantaneous picture of the turbulent flow field, whereas the long-time exposure averages the small, rapidly varying scales and gives a clearer representation of the large scales. A correlation technique involving the light intensity of the photographs made it possible to obtain, in an objective manner, both the spanwise and streamwise wavelengths of the flow structures. During these experiments 17 different flow regimes have been identified, both laminar and turbulent with and without roll cells, as well as states that can be described as transitional, i.e. states that contain both laminar and turbulent regions at the same time. Many of these flow states seem to be similar to those observed in Taylor Couette flow.
Place, publisher, year, edition, pages
2010. Vol. 648, 5-33 p.
CHANNEL FLOW, TRANSITION, TURBULENCE, INSTABILITIES, VISUALIZATION, CYLINDERS, STABILITY, LAMINAR, SPOTS
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-28229DOI: 10.1017/S0022112009993880ISI: 000277255000002ScopusID: 2-s2.0-77952385761OAI: oai:DiVA.org:kth-28229DiVA: diva2:389476
FunderSwedish Research Council
QC 201101192011-01-192011-01-122011-01-19Bibliographically approved