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Numerical Simulation of Flow Characteristics behind a Circular Patch of Vegetation using a Two-Dimensional Numerical Model
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 Title & Authors
Numerical Simulation of Flow Characteristics behind a Circular Patch of Vegetation using a Two-Dimensional Numerical Model
Kim, Hyung Suk; Park, Moonhyeong;
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 Abstract
This paper presents numerical simulations of flow around a circular patch of vegetation using a depth-averaged two-dimensional numerical model which is capable of simulating flow structure in vegetated open channel. In order to account for vegetation effect, drag force terms are included in governing equations. Numerical simulations are conducted with various solid volume fractions (SVF). Flow passes through a circular patch and low velocity region, which is called wake region, is formed downstream of the patch. When SVF is larger than 0.08, a recirculation is observed. The location of the recirculation is moved further downstream as SVF decreases. Von- vortex street is developed beyond the wake region due to interaction between two shear layers induced by a circular patch of vegetation. The vortex is developed as SVF is larger than 0.08, and the location of the vortex is consistent with the maximum of turbulence kinetic energy. The location of the peak of turbulence kinetic energy is moved further downstream as SVF decreases.
 Keywords
open channel;vegetation;shear layer;vortex;two-dimensional numerical model;
 Language
Korean
 Cited by
 References
1.
Bosch, G., and Rodi, W. (1998). "Simulation of vortex shedding past a square cylinder with dierent turbulence models." International Journal for Numerical Methods in Fluids, Vol. 28, pp. 601-616. crossref(new window)

2.
Boussinesq, J. (1877). "Essai sur la theorie des eaux courantes." Memoires presentes par divers savants a l'Academie des Sciences, XXIII, 1, pp. 1-680.

3.
Chang, K.S., and Constantinescu, G. (2012). "LES of flow past a porous cylinder." River Flow 2012, Vol. 1, pp. 225-231.

4.
Chen, Z., Ortiz, A., Zong, L., and Nepf, H. (2012). "The wake structure behind a porous obstruction and its implications for deposition near a finite patch of emergent vegetation." Water Resources Research, Vol. 48, W09517.

5.
Choi, S., Choi, S.-U., and Kim, T. (2014). "Numerical simulation of mean flows and turbulent structures of partly-vegetated open channel flows using the nonlinear k-${\varepsilon}$ model." Journal of Korean Society of Civil Engineers, Vol. 34, No. 3, pp. 813-820 (in Korean). crossref(new window)

6.
Choi, S.-U., and Kang, H. (2006). "Numerical investigations of mean flow and turbulence structures of partly vegetated open channel flows using the Reynolds stress model." Journal of Hydraulic Research, Vol. 44, No. 2, pp. 203-217. crossref(new window)

7.
Cotton, J., Wharton, G., Bass, J., Heppell, C., and Wotton, R. (2006). "The effects of seasonal changes to in-stream vegetation cover on patterns of flow and accumulation of sediment." Geomorphology, Vol. 77, pp. 210-334.

8.
Dunn, C., Lopez, F., and Garcia, M. (1996). "Mean flow and turbulence in a laboratory channel with simulated vegetation." Hydraulic engineering Series Rep. 1, Univ. Illinois at Urbana-Champaign.

9.
Fletcher, C.A.J. (1991). "Computaional techniques for fluid dynamics." Vol. II, Springer-Verlag, Berlin, Germany.

10.
Fukuoka, S., Watanabe, A., Takatsugu, W., and Sakamoto, H. (2001). "Mixing structure and flow development accompaning the change in the density of vegetation along a compound main channel banks." Annual Journal of Japan Society of Civil Engineers, Vol. 45, pp. 859-864 (in Japanese).

11.
Kang, H. (2013). "Flow characteristics and morphological changes in open-channel flows with alternate vegetation zones." Journal of Korean Society of Civil Engineers, Vol. 17, No. 5, pp. 1157-1165.

12.
Kang, H., and Choi, S.-U. (2007). "Numerical investigations of streamwise vortical structures om fully vegetated open channel flows." Journal of Korean Society of Civil Engineers, Vol. 27, No. 3B, pp. 289-299 (in Korean).

13.
Kim, H.S., Kimura, I., and Shimizu, Y. (2015). "Bed morphological changes around a finite patch of vegetation." Earth Surface processes and Landforms, Vol. 40, No. 3, pp. 375-388. crossref(new window)

14.
Kwon, K., and Choi, S.-U. (2000). "Analysis of vegetated open-channel flows using the k-${\varepsilon}$ turbulence model." Journal of Korean Society of Civil Engineers, Vol. 20, No. 1B, pp. 11-21 (in Korean).

15.
Launder, B.E., and Spalding, D.B. (1974). "The numerical computation of turbulent flow." Computer Methods in Applied Mechanics and Engineering, Vol. 3, pp. 269-289. crossref(new window)

16.
Lopez, F., and Garcia, M. (1997). "Open channel flow through simulated vegetation: turbulence modeling and sediment transport." Wetland Research Program Technical Report WRP-CP-10, Waterways Experiment Station, Vicksburg, MS.

17.
Lyn, D.A., Einav, W., Rodi, W., and Park, J-H. (1995). "A laser-doppler velocimetry study of ensembleaveraged characteristics of the turbulent near wake of a square cylinder." Journal of Fluid Mechanics, Vol. 304, pp. 285-319. crossref(new window)

18.
Moore, K.A. (2004). "Influence of seagrasses on water quality in shallow regions of the lower Chesapeake bay." Journal of Coastal Research, Vol. 20, pp. 162-178.

19.
Nepf, H. (1999). "Drag, turbulence, and diffusion in flow through emergent vegetation." Water Resources Research, Vol. 35, No. 2, pp. 479-489. crossref(new window)

20.
Nepf, H., and Vivoni, E.R. (2000). "Flow structure in depth-limited vegetated flow." Journal of Geophysical Research, Vol. 105, No. 28, pp. 547-557.

21.
Nicolle, A., and Eames, I. (2011). "Numerical study of flow through and around a circular array of cylinders." Journal of Fluid Mechanics, Vol. 679, pp. 1-31. crossref(new window)

22.
Rodi, W. (1993). Turbulence modeling and their application in hydraulics. Monograph, IAHR, Delft, The Netherlands.

23.
Rominger, J., and Nepf, H. (2011). "Flow adjustment and interiorflow associated with a rectangular porous obstruction." Journal of Fluid Mechanics, Vol. 679, pp. 1-31. crossref(new window)

24.
Schultz, M., Kozerski, H.-P., Pluntke, T., and Rinke, K. (2003). "The influence of macrophytes on sedimentation and nutrient retention in the lower river spree." Water Resources Research, Vol. 37, pp. 569-578. crossref(new window)

25.
Stone, B.M., and Shen, H.T. (2002). "Hydraulic resistance of flow in channels with cylindrical roughness." Journal ofHydraulic Engineering, Vol. 128, No. 5, pp. 500-506. crossref(new window)

26.
Takemura, T., and Tanaka, N. (2007). "Flow structures and drag characteristics of a colony-type emergent roughness model mounted on a flat plate in uniform flow." Fluid Dynamics Research, Vol. 39, pp. 694-710. crossref(new window)

27.
Tal, M., and Paola, C. (2007). "Dynamic single-thread channels maintained by the interactions flow and vegetation." Geology, Vol. 35. No. 4, pp. 347-350.

28.
Tanino, Y., and Nepf, H.M. (2008). "Laboratory investigation of mean drag in a random array of rigid, emergent cylinders." Journal of Hydraulic Engineering, Vol. 134, No. 1, pp. 34-41. crossref(new window)

29.
White, B., and Nepf, H. (2007). "A vortex-based model of velocity and shear stress in a partially vegetated shallow channel." Water Resources Research, Vol. 44,W01412.

30.
Williamson, C.H.K. (1996). "Vortex dynamics in the cylinder wake." Annual Review of Fluid Mechanics, Vol. 28, pp. 477-539. crossref(new window)

31.
Wu, W., Shields, F.D. Jr., Bennett, S., and Wang, S S Y. (2005). "A depth-averaged two-dimensional model for flow, sediment transport, and bed topography in curved channels with riparian vegetation." Water Resources Research, Vol. 41, W03015.

32.
Zong, L., and Nepf, H. (2010). "Flow and deposition in and around a finite patch of vegetation." Geomorphology, Vol. 116, pp. 363-372. crossref(new window)

33.
Zong, L., and Nepf, H. (2011). "Spatial distribution of deposition within a patch of vegetation." Water Resources Research, Vol. 47, W03516.

34.
Zong, L., and Nepf, H. (2012). "Vortex development behind a finite porous obstruction in a channel." Journal of Fluid Mechanics, Vol. 691, pp. 368-391. crossref(new window)