Instabilities and small-scale waves within the Stewartson layers of a thermally driven rotating annulus. (21st February 2018)

• Record Type: Journal Article
• Authors: von Larcher, Thomas; Viazzo, Stéphane; Harlander, Uwe; Vincze, Miklos; Randriamampianina, Anthony
• Is Part Of: Journal of fluid mechanics. Volume 841(2018)
• Page Start: 380
• Page End: 407
• Publication Date: 2018-02-21
• Subjects: baroclinic flows, -- geophysical and geological flows, -- internal waves; Fluid mechanics -- Periodicals; 532.005
• DOI: 10.1017/jfm.2018.10
• Languages: English
• ISSNs: 0022-1120

Abstract

Abstract : We report on small-scale instabilities in a thermally driven rotating annulus filled with a liquid with moderate Prandtl number. The study is based on direct numerical simulations and an accompanying laboratory experiment. The computations are performed independently with two different flow solvers, that is, first, the non-oscillatory forward-in-time differencing flow solver EULAG and, second, a higher-order finite-difference compact scheme (HOC). Both branches consistently show the occurrence of small-scale patterns at both vertical sidewalls in the Stewartson layers of the annulus. Small-scale flow structures are known to exist at the inner sidewall. In contrast, short-period waves at the outer sidewall have not yet been reported. The physical mechanisms that possibly trigger these patterns are discussed. We also debate whether these small-scale structures are a gravity wave signal.