On three-dimensional geophysical capillary–gravity water flows with constant vorticity

2020 ◽  
Author(s):  
Lili Fan ◽  
Hongjun Gao
Keyword(s):  
Three Dimensional ◽  
Water Flows ◽  
Constant Vorticity

On constant vorticity water flows in the -plane approximation

2019 ◽  
Vol 865 ◽  
pp. 762-774 ◽  
Author(s):  
Calin Iulian Martin
Keyword(s):  
Free Surface ◽  
Velocity Field ◽  
Three Dimensional ◽  
General Setting ◽  
Stationary Flow ◽  
Water Flows ◽  
Constant Vorticity ◽  
Vorticity Vector

We consider here three-dimensional water flows in the $\unicode[STIX]{x1D6FD}$-plane approximation. In a quite general setting we show that the only flow exhibiting a constant vorticity vector is the stationary flow with vanishing velocity field and flat free surface.

scholarly journals Constant vorticity water flows with full Coriolis term

Nonlinearity ◽  
2019 ◽  
Vol 32 (7) ◽  
pp. 2327-2336 ◽  
Author(s):  
Calin Iulian Martin
Keyword(s):  
Water Flows ◽  
Constant Vorticity

Quasi-two-layer finite-volume scheme for modelling shallow water flows over an arbitrary bed in the presence of external force. II. Algorithm applications and numerical results

2014 ◽  
Vol 29 (3) ◽  
Author(s):  
Kirill V. Karelsky ◽  
Arakel S. Petrosyan ◽  
Alexander G. Slavin
Keyword(s):  
Shallow Water ◽  
Finite Volume ◽  
External Force ◽  
Large Scale ◽  
Lower Layer ◽  
Three Dimensional ◽  
Finite Volume Scheme ◽  
Water Flows ◽  
Shallow Water Flows ◽  
Scale Motion

AbstractA finite-volume numerical method for studying shallow water flows over an arbitrary bed profile in the presence of external force has been proposed in [33]. This method uses the quasi-two-layer model of hydrodynamic flows over a stepwise boundary with advanced consideration of the flow features near the step. A distinctive feature of the suggested model is a separation of the studied flow into two layers in calculating the flow quantities near each step, and improving by this means the approximation of depth-averaged solutions of the initial three-dimensional Euler equations. We are solving the shallow-water equations for one layer, introducing the fictitious lower layer only as an auxiliary structure in setting up the appropriate Riemann problems for the upper layer. Besides, the quasi-two-layer approach leads to the appearance of additional terms in the one-layer finite-difference representation of balance equations. Numerical simulations are performed based on the proposed in [33] algorithm of various physical phenomena, such as breakdown of the rectangular fluid column over an inclined plane, large-scale motion of fluid in the gravity field in the presence of Coriolis force over amounted obstacle on the underlying surface. Computations are made for the two-dimensional dam-break problem on a slope precisely conform to laboratory experiments. The interaction of the Tsunami wave with the shore line including an obstacle has been simulated to demonstrate the efficiency of the developed algorithm in domains, including partly flooded and dry regions.

scholarly journals In vivo intraoral waterflow quantification reveals hidden mechanisms of suction feeding in fish

2021 ◽  
Author(s):  
Pauline Provini ◽  
Alexandre Brunet ◽  
Andréa Filippo ◽  
Sam Van Wassenbergh
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
New Technique ◽  
Fish Feed ◽  
Suction Feeding ◽  
Apparent Paradox ◽  
X Ray ◽  
Water Flows ◽  
Food Transport

Virtually all fish rely on flows of water to transport food to the back of their pharynx. While external flows that draw food into the mouth are well described, how intra-oral water flows manage to deposit food at the esophagus entrance remains unknown. In theory, the posteriorly moving water must, at some point, curve laterally and/or ventrally to exit through the gill slits. Such flows would eventually carry food away from the esophagus instead of towards it. This apparent paradox calls for a filtration mechanism to deviate food from the suction-feeding streamlines. To study this gap in our fundamental understanding of how fish feed, we developed and applied a new technique to quantify three-dimensional patterns of intra-oral water flows in vivo. We combined stereoscopic high-speed x-ray videos to quantify skeletal motion (XROMM) with 3D x-ray particle tracking (XPT) of approximately neutrally buoyant spheres of 1.4 mm in diameter. We showed, for carp (Cyprinus carpio) and tilapia (Oreochromis niloticus), that water tracers displayed higher curvatures than food tracers, indicating an inertia-driven filtration. In addition, tilapia also exhibited a 'central jet' flow pattern, which aids in quickly carrying food to the pharyngeal jaw region. When the food was trapped at the branchial basket, it was resuspended and carried more centrally by periodical bidirectional waterflows, synchronized with head-bone motions. By providing a complete picture of the suction-feeding process and revealing fundamental differences in food transport mechanisms among species, this new technique opens a new area of investigation to fully understand how most aquatic vertebrates feed.

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