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HYDRODYNAMICS AND ACOUSTICS
2019 ◊ Volume 1 (91) ◊ Issue 4 ◊ p. 377-407
A. A. Gourjii*, V. I. Osadchyy**, E. I. Nikiforovich***, O. I. Kordas****, D. I. Cherniy*****
* National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", Kyiv, Ukraine
** Ukrainian Hydrometeorological Institute, SES of Ukraine and NAS of Ukraine, Kyiv, Ukraine
*** Institute of Hydromechanics of NAS of Ukraine, Kyiv, Ukraine
**** KTH Royal Institute of Technology, Stockholm, Sweden
***** Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
Modeling the process of surface impurity transfer in deltas of river systems
Gidrodin. akust. 2019, 1(4):377-407
TEXT LANGUAGE: Russian
ABSTRACT
The problem of two-dimensional advection of a passive pollution by surface flows in the delta of river systems with complex geometry of the coastline in approximation of an ideal incompressible fluid. The problem is solved by numerical method of discrete singularities adapted to fluid advection problems. The model provides for the preliminary digitization of the shoreline, which is associated with the system of collocation points located along the coastline and system of fixed point vortices, following certain recommendations. The mathematical model allows to take into account the influence of wind on the distribution processes of allocated passive fluid (pollution) in the flow under consideration. To do this, a system of vortons placed in the dynamic system above the calculated surface is introduced. An illustrative example of the evolution of the surface pollution in the Dnieper-Bug estuary, formed in lower reach of Dnepr River and the Yuzhny Bug River. It is shown that the effect of wind leads to significant changes in motion of the separated fluid. In particular, the formation of circulation flow zones leads to a significant slowing of velocity motion of the pollution and its displacement in transverse direction with respect to the main flow. The analysis of quantitative data shows that the area of pollution on the lagoon water area is substantially increases under the influence of a moderate wind with different directions in comparison with the case of fluid advection with absence of wind.
KEY WORDS
advection, surface current, pollution, method of discrete singularities, Dnieper-Bug estuary
REFERENCES