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Exchange flow between a canopy and open water

Jamali, M ; Sharif University of Technology | 2008

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  1. Type of Document: Article
  2. DOI: 10.1017/S0022112008002796
  3. Publisher: 2008
  4. Abstract:
  5. This paper theoretically and experimentally investigates the exchange flow due to temperature differences between open water and a canopy of aquatic plants. A numerical model is used to study the interfacial shape, frontal velocity and total volumetric exchange, and their dependence on a dimensionless vegetation drag parameter. The numerical predictions are consistent with the laboratory measurements. There is a short initial period in which the force balance is between buoyancy and inertia, followed by drag-dominated flow for which there is a balance between buoyancy and drag forces. After the initial stage, the gravity current propagating into the canopy takes a triangular shape whereas the current propagating into the open water has almost the classic unobstructed horizontal profile, but with a slowly decreasing depth. Near the edge of the canopy, but in the open region, the flow is found to be critical with a unit internal Froude number. The exchange flow rate and the front speed in the canopy decrease slowly with time whereas the gravity current in the open water has a constant speed. The magnitude of the exchange flow decreases as the canopy drag increases. Empirical equations for the flow properties are presented. A movie is available with the online version of the paper. © 2008 Cambridge University Press
  6. Keywords:
  7. Aquaculture ; Buoyancy ; Extractive metallurgy ; Fluid mechanics ; Gravitational effects ; Gravity waves ; Numerical methods ; Speed ; Exchange flow ; Open water ; Drag ; Empirical analysis ; Froude number ; Numerical model
  8. Source: Journal of Fluid Mechanics ; Volume 611 , 25 September , 2008 , Pages 237-254 ; 00221120 (ISSN)
  9. URL: https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/abs/exchange-flow-between-a-canopy-and-open-water/04C83DB69548182CB445690E3FC07913