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Stability and the transition to turbulence in the flow through conduits with compliant walls

Kumaran, V (2021) Stability and the transition to turbulence in the flow through conduits with compliant walls. In: Journal of Fluid Mechanics, 924 .

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Official URL: https://doi.org/10.1017/jfm.2021.602


The mechanisms of destabilisation of the flow through soft-walled channels/tubes are qualitatively different from those in rigid-walled conduits. The stability depends on two dimensionless parameters, the Reynolds number and, where and are the fluid density and viscosity, and are the fluid length and velocity scale and is the wall elasticity modulus. There is an instability at zero Reynolds number when the dimensionless parameter exceeds a critical value. The low-Reynolds-number instability of the Couette flow past a compliant surface is well understood, and has been confirmed in experiments, but that in a pressure-driven flow is not completely understood. Two modes of instability at high Reynolds number have been predicted: the inviscid mode with an internal viscous layer, for which the transition Reynolds number scales as; and the wall mode instability with a viscous layer at the wall, for which. The wall mode instability has been observed in experiments at Reynolds number as low as 300 in a soft-walled tube and as low as 100 in a channel with one compliant wall, though the scaling of the transition Reynolds number differs from the theoretical prediction due to substantial wall deformation. Though the flow after transition shares many of the characteristics of hard-wall turbulence, it differs in significant ways, suggesting that soft-wall turbulence is a separate class distinct from hard-wall turbulence. © 2021 Cambridge University Press. All rights reserved.

Item Type: Journal Article
Publication: Journal of Fluid Mechanics
Publisher: Cambridge University Press
Additional Information: The copyright for this article belongs to Authors
Keywords: Channel flow; Reynolds number; Turbulence, Compliant surfaces; Dimensionless parameters; High Reynolds number; Low Reynolds number; Pressure-driven flows; Transition Reynolds number; Transition to turbulence; Wall deformation, Stability, Couette flow; density; flow velocity; qualitative analysis; Reynolds number; theoretical study; turbulence; viscosity
Department/Centre: Division of Mechanical Sciences > Chemical Engineering
Date Deposited: 21 Nov 2021 16:28
Last Modified: 21 Nov 2021 16:28
URI: http://eprints.iisc.ac.in/id/eprint/69932

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