BUCKLING FLOWS: A NEW FRONTIER IN FLUID MECHANICS.
The objective of this review is to draw attention to recent advances in a relatively new subfield of fluid mechanics research, namely, the study of the buckling or meandering tendency exhibited by some flows at sufficiently high Reynolds numbers. Buckling flows appear to be governed by a number of common features, the most important being the proportionality between the buckling wavelength and the transversal length scale of the stream. The experimental evidence on buckling flows is reviewed in the first part of the article. The photographic record suggests that the wavelength approximate thickness scaling law governs also the large scale meandering structure of high Reynolds number jets, wakes and plumes, in other words, that the large scale structure of turbulent streams can be regarded as the fingerprint of buckling. The theoretical attempts that have been made in order to explain the buckling phenomenon are reviewed as an invitation to continued research.
