Interaction of viscous free-surface flows with topography
| Autor: | Herbert E. Huppert, Andrew J. Hogg, Edward M. Hinton |
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| Rok vydání: | 2019 |
| Předmět: |
Length scale
010504 meteorology & atmospheric sciences Lava Mechanical Engineering Mechanics Wake Viscous liquid 010502 geochemistry & geophysics Condensed Matter Physics 01 natural sciences Amplitude Flow (mathematics) Mechanics of Materials Free surface Lubrication Geology 0105 earth and related environmental sciences |
| Zdroj: | Hinton, E, Hogg, A & Huppert, H 2019, ' Interaction of viscous free-surface flows with topography ', Journal of Fluid Mechanics, vol. 876, pp. 912-938 . https://doi.org/10.1017/jfm.2019.588 |
| ISSN: | 1469-7645 0022-1120 |
| Popis: | The interaction of gravitationally driven, free-surface flows of viscous fluid with topographic features is investigated theoretically. The motion is studied in the regime where the depth of the flow is much smaller than the streamwise extent of the topography. A lubrication model of the motion is developed, integrated numerically and analysed asymptotically. For small mounds, it is shown that the flow surmounts the obstacles, but for larger mounds the flow is deflected around it and can form dry zones in its wake into which fluid does not flow, as well as forming deeper ponded regions upstream. Which of these phenomena prevails is shown to depend upon the amplitude of the mound height and the thickness of the oncoming flow relative to the streamwise length scale over which the topography varies. By using numerical and asymptotic results, we demonstrate that relatively wide mounds lead to the development of deep ponds of material upstream, which may lead to flow overtopping if the mound is not sufficiently high. These insights can be used to inform the design of barriers that defend built infrastructures from lava flows, and it is shown how this model can also provide an upper bound on the force exerted by the flow on them. |
| Databáze: | OpenAIRE |
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