Keeler, J. S. ORCID: https://orcid.org/0000-0002-8653-7970, Binder, B. J. and Blyth, M. G.
(2017)
On the critical free-surface flow over localised topography.
Journal of Fluid Mechanics, 832.
pp. 73-96.
ISSN 0022-1120
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Abstract
Flow over bottom topography at critical Froude number is examined with a focus on steady, forced solitary wave solutions with algebraic decay in the far-field, and their stability. Using the forced Korteweg-de Vries (fKdV) equation the weakly-nonlinear steady solution space is examined in detail for the particular case of a Gaussian dip using a combination of asymptotic analysis and numerical computations. Non-uniqueness is established and a seemingly infinite set of steady solutions is uncovered. Non-uniqueness is also demonstrated for the fully nonlinear problem via boundary-integral calculations. It is shown analytically that critical flow solutions have algebraic decay in the far-field both for the fKdV equation and for the fully nonlinear problem and, moreover, that the leading-order form of the decay is the same in both cases. The linear stability of the steady fKdV solutions is examined via eigenvalue computations and by a numerical study of the initial value fKdV problem. It is shown that there exists a linearly stable steady solution in which the deflection from the otherwise uniform surface level is everywhere negative.
Item Type: | Article |
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Faculty \ School: | Faculty of Science > School of Mathematics |
UEA Research Groups: | Faculty of Science > Research Groups > Fluid and Solid Mechanics |
Depositing User: | Pure Connector |
Date Deposited: | 01 Sep 2017 05:08 |
Last Modified: | 22 Oct 2022 03:06 |
URI: | https://ueaeprints.uea.ac.uk/id/eprint/64716 |
DOI: | 10.1017/jfm.2017.639 |
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