0
Research Papers: Flows in Complex Systems

Drag and Turbulent Characteristics of Mobile Bed Channel With Mixed Vegetation Densities Under Downward Seepage

[+] Author and Article Information
Thokchom Bebina Devi

Department of Civil Engineering,
Indian Institute of Technology Guwahati,
Guwahati 781039, India
e-mail: thokchom@iitg.ernet.in

Rishabh Daga, Sumit Kumar Mahto

Department of Civil Engineering,
Indian Institute of Technology Guwahati,
Guwahati 781039, India

Bimlesh Kumar

Associate Professor
Department of Civil Engineering,
Indian Institute of Technology Guwahati,
Guwahati 781039, India
e-mail: bimk@iitg.ernet.in

1Corresponding author.

Contributed by the Fluids Engineering Division of ASME for publication in the JOURNAL OF FLUIDS ENGINEERING. Manuscript received June 27, 2015; final manuscript received January 19, 2016; published online April 22, 2016. Assoc. Editor: D. Keith Walters.

J. Fluids Eng 138(7), 071104 (Apr 22, 2016) (13 pages) Paper No: FE-15-1431; doi: 10.1115/1.4032753 History: Received June 27, 2015; Revised January 19, 2016

The present study addresses the drag owing to the presence of vegetation and turbulent characteristics in a mobile bed channel, characterized by fully submerged vegetation formed by nonuniform vegetation densities. The influence of seepage on the velocity profiles, Reynolds stress, and turbulence intensities is discussed. Experimental results show that vegetation density is one of the important parameters that affect the flow resistance. It is found that higher vegetation density when placed at the downstream side leads to a reduction in velocity, Reynolds stress, and turbulent intensities. Downward seepage increases the near bed velocity, Reynolds stress, and turbulent intensities. Moment analysis shows that there is an increase in the inrush of flow, and sediment particles are transported more toward the streamwise direction with the application of seepage. The dominance of sweep events over ejection events increases more sediment transport. However, high vegetation density when placed at the downstream portion slightly decreases the dominance of sweep event. Drag coefficient decreases near the vegetation top and increases near the bed. Downward seepage decreases the effect of drag offered by the vegetation stems. The reduction in flow characteristics, viz., velocity, Reynolds stress, turbulent intensities, in the downstream portion of lesser spacing vegetation stems is attributed an increased drag coefficient.

FIGURES IN THIS ARTICLE
<>
Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.

References

Nepf, H. M. , and Vivoni, E. R. , 2000, “ Flow Structure in Depth-Limited, Vegetated Flow,” J. Geophys. Res., 105, pp. 28547–28557. [CrossRef]
Ghisalberti, M. , and Nepf, H. , 2005, “ Mass Transport in Vegetated Shear Flows,” Environ. Fluid Mech., 5(6), pp. 527–551. [CrossRef]
Hongwu, T. , Wang, H. , Liang, D. , Lv, S. , and Yan, L. , 2013, “ Incipient Motion of Sediment in the Presence of Emergent Rigid Vegetation,” J. Hydro-Environ. Res., 7(3), pp. 202–208. [CrossRef]
Wang, H. , Tang, H. , Yuan, S. , Lv, S. , and Zhao, X. , 2014, “ An Experimental Study of the Incipient Bed Shear Stress Partition in Mobile Bed Channels Filled With Emergent Rigid Vegetation,” Sci. China: Technol. Sci., 57(6), pp. 1165–1174. [CrossRef]
Zhang, H. , Wang, Z. , Dai, L. , and Xu, W. , 2015, “ Influence of Vegetation on Turbulence Characteristics and Reynolds Shear Stress in Partly Vegetated Channel,” ASME J. Fluids Eng., 137(6), p. 061201. [CrossRef]
Nepf, H. M. , 2012, “ Flow and Transport in Regions With Aquatic Vegetation,” Annu. Rev. Fluid Mech., 44(1), pp. 123–142. [CrossRef]
Poggi, D. , Porporato, A. , and Ridolfi, L. , 2004, “ The Effect of Vegetation Density on Canopy Sub-Layer Turbulence,” Boundary Layer Meteorol., 111(3), pp. 565–587. [CrossRef]
Carollo, F. G. , Ferro, V. , and Termini, D. , 2005, “ Flow Resistance Law in Channels With Flexible Submerged Vegetation,” J. Hydraul. Eng., 131(7), pp. 554–564. [CrossRef]
Chen, S. C. , Kuo, Y. M. , and Li, Y. H. , 2011, “ Flow Characteristics Within Different Configurations of Submerged Flexible Vegetation,” J. Hydrol., 398, pp. 124–134. [CrossRef]
Finnigan, J. , 2000, “ Turbulence in Plant Canopies,” Annu. Rev. Fluid Mech., 32(1), pp. 519–571. [CrossRef]
Ghisalberti, M. , and Nepf, H. , 2006, “ The Structure of Shear Layer in Flows Over Rigid and Flexible Canopies,” Environ. Fluid Mech., 6(6), pp. 277–301. [CrossRef]
Raupach, M. R. , Finnigan, J. J. , and Brunet, Y. , 1996, “ Coherent Eddies and Turbulence in Vegetation Canopies: The Mixing Layer Analogy,” Boundary-Layer Meteorol., 78, pp. 351–382. [CrossRef]
Nathan, R. , Katul, G. G. , Horn, H. S. , Thomas, S. M. , Oren, R. , Avissar, R. , Pacala, S. W. , and Levin, S. A. , 1977, “ Mechanisms of Long-Distance Dispersal of Seeds by Wind,” Nature, 418, pp. 409–413. [CrossRef]
Scanlon, T. M. , Albertson, J. D. , Caylor, K. K. , and Williams, C. A. , 2002, “ Determining Land Surface Fractional Cover From NDVI and Rainfall Time Series for a Savanna Ecosystem,” Remote Sens. Environ., 82, pp. 376–388. [CrossRef]
Nezu, I. , 2005, “ Open-Channel Flow Turbulence and Its Research Prospect in the 21st Century,” J. Hydraul. Eng., 131(4), pp. 229–246. [CrossRef]
Tanino, Y. , and Nepf, H. M. , 2008, “ Laboratory Investigation of Mean Drag in a Random Array of Rigid, Emergent Cylinders,” J. Hydraul. Eng., 134(1), pp. 34–41. [CrossRef]
Cowan, W. L. , 1956, “ Estimating Hydraulic Roughness Coefficients,” Agric. Eng., 37(7), pp. 473–475.
Tsujimoto, T. , 1999, “ Fluvial Processes in Streams With Vegetation,” J. Hydraul. Res., 37(6), pp. 789–803. [CrossRef]
Duan, J. G. , Barkdoll, B. , and French, R. , 2006, “ Lodging Velocity for an Emergent Aquatic Plant in Open Channels,” J. Hydraul. Eng., 132(10), pp. 1015–1020. [CrossRef]
Fisher, K. , 1992, “ The Hydraulic Roughness of Vegetated Channels,” Report SR No. 305.
Luhar, M. , and Nepf, H. M. , 2013, “ From the Blade Scale to the Reach Scale: A Characterization of Aquatic Vegetative Drag,” Adv. Water Resour., 51, pp. 305–316. [CrossRef]
Kim, H. S. , Kimura, I. , and Shimizu, Y. , 2015, “ Bed Morphological Changes Around a Finite Patch of Vegetation,” Earth Surf. Processes Landforms, 40(3), pp. 375–388. [CrossRef]
Meijer, D. G. , and Van Velzen, E. H. , 1999, “ Prototype-Scale Flume Experiments on Hydraulic Roughness of Submerged Vegetation,” 28th International IAHR Conference, Graz, Austria.
Stephan, U. , and Gutknecht, D. , 2002, “ Hydraulic Resistance of Submerged Flexible Vegetation,” J. Hydrol., 269, pp. 27–43. [CrossRef]
Järvelä, J. , 2002, “ Flow Resistance of Flexible and Stiff Vegetation: A Flume Study With Natural Plants,” J. Hydrol., 269, pp. 44–54. [CrossRef]
Righetti, M. , and Armanini, A. , 2002, “ Flow Resistance in Open Channel Flows With Sparsely Distributed Bushes,” J. Hydrol., 269, pp. 55–64. [CrossRef]
Klopstra, D. , Barneveld, H. J. , Van Noortwijk, J. M. , and Van Velzen, E. H. , 1997, “ Analytical Model for Hydraulic Roughness of Submerged Vegetation,” 27th International IAHR Conference, San Francisco, CA.
Kouwen, N. , and Li, R. M. , 1980, “ Biomechanics of Vegetative Channel Linings,” J. Hydraul. Div., 106(HY6), pp. 1085–1103.
Fathi-Maghadam, M. , and Kouwen, N. , 1997, “ Nonrigid, Nonsubmerged, Vegetative Roughness on Floodplains,” J. Hydraul. Eng., 123(1), pp. 51–57. [CrossRef]
Nepf, H. M. , and Vivoni, E. R. , 1999, “ Turbulence Structure in Depth-Limited Vegetated Flow: Transition Between Emergent and Submerged Regimes,” 28th International IAHR Conference, Graz, Austria.
Fischer-Antze, T. , Stoesser, T. , Bates, P. , and Olsen, N. R. B. , 2001, “ 3D Numerical Modelling of Open Channel Flow With Submerged Vegetation,” J. Hydraul. Res., 39(3), pp. 303–310. [CrossRef]
López, F. , and García, M. H. , 2001, “ Mean Flow and Turbulence Structure of Open-Channel Flow Through Non-Emergent Vegetation,” J. Hydraul. Eng., 127(5), pp. 392–402. [CrossRef]
Nakagawa, H. , Tsujimoto, T. , and Shimizu, Y. , 1992, “ Sediment Transport in Vegetated Bed Channel,” 5th International Symposium on River Sedimentation, Karlsruhe, Germany.
Watanabe, Y. , and Hoshi, K. , 1996, “ Influence of Vegetation on Flow Velocity and Suspended Load,” International Workshop on Interactive Issues of Flood and Environment in Cold Regions, Trento, Italy, Oct. 3–6.
Houwing, E. J. , Tanczos, I. C. , Kroon, A. , and De Vries, M. B. , 2000, “ Interaction of Submerged Vegetation, Hydrodynamics and Turbidity; Analysis of Field and Laboratory Results,” INTERCOH Conference.
Teeter, A. M. , Johnson, B. H. , Berger, C. , Stelling, G. , Scheffner, N. W. , Garcia, M. H. , and Parchure, T. M. , 2001, “ Hydrodynamic and Sediment Transport Modelling With Emphasis on Shallow-Water, Vegetated Areas (Lakes, Reservoirs, Estuaries and Lagoons),” Hydrobiologia, 444(1), pp. 1–23. [CrossRef]
Madsen, J. D. , Chambers, P. A. , James, W. F. , Koch, E. W. , and Westlake, D. F. , 2001, “ The Interaction Between Water Movement, Sediment Dynamics and Submersed Macrophytes,” Hydrobiologia, 444, pp. 71–84. [CrossRef]
Nepf, H. M. , 1999, “ Drag, Turbulence, and Diffusion in Flow Through Emergent Vegetation,” Water Resour. Res., 35(2), pp. 479–489. [CrossRef]
Finnigan, J. J. , Shaw, R. H. , and Patton, E. G. , 2009, “ Turbulence Structure Above a Vegetation Canopy,” J. Fluid Mech., 637, pp. 387–424. [CrossRef]
Nezu, I. , and Onitsuka, K. , 2001, “ Turbulent Structure in Partly Vegetated Open Channel Flows With LDA and PIV Measurements,” J. Hydraul. Res., 39(6), pp. 629–642. [CrossRef]
Wilson, C. A. M. E. , Stoesser, T. , Bates, P. D. , and Pinzen, A. B. , 2003, “ Open Channel Flow Through Different Forms of Submerged Flexible Vegetation,” J. Hydraul. Eng., 129(11), pp. 847–853. [CrossRef]
Luna, A. V. , Crosato, A. , and Uijttewaal, W. S. J. , 2015, “ Effects of Vegetation on Flow and Sediment Transport: Comparative Analyses and Validation of Predicting Models,” Earth Surf. Processes Landforms, 40(2), pp. 157–176. [CrossRef]
de Lima, P. H. S. , Janzen, J. G. , and Nepf, H. M. , 2015, “ Flow Patterns Around Two Neighboring Patches of Emergent Vegetation and Possible Implications for Deposition and Vegetation Growth,” Environ. Fluid Mech., 15(4), pp. 881–898. [CrossRef]
Tanji, K. K. , and Kielen, N. C. , 2002, “ Agricultural Drainage Water Management in Arid and Semi-Arid Areas,” Irrigation and Drainage Paper, FAO, Rome, Italy.
Kinzli, K.-D. , Martinez, M. , Oad, R. , Prior, A. , and Gensler, D. , 2010, “ Using an ADCP to Determine Canal Seepage Loss in an Irrigation District,” Agric. Water Manage., 97(6), pp. 801–810. [CrossRef]
Martin, C. A. , and Gates, T. K. , 2014, “ Uncertainty of Canal Seepage Losses Estimated Using Flowing Water Balance With Acoustic Doppler Devices,” J. Hydrol., 517, pp. 764–761. [CrossRef]
Richardson, J. R. , Abt, S. R. , and Richardson, E. V. , 1985, “ Inflow Seepage Influence on Straight Alluvial Channels,” J. Hydraul. Eng., 111(8), pp. 1133–1147. [CrossRef]
Maclean, A. G. , 1991, “ Open Channel Velocity Profiles Over a Zone of Rapid Infiltration,” J. Hydraul. Res., 29(1), pp. 15–27. [CrossRef]
Rao, A. R. , Subrahmanyam, V. , Thayumanavan, S. , and Namboodiripad, D. , 1994, “ Seepage Effects on Sand Bed Channels,” J. Irrig. Drain. Eng., 120(1), pp. 60–79. [CrossRef]
Chen, X. , and Chiew, Y.-M. , 2004, “ Velocity Distribution of Turbulent Open Channel Flow With Bed Suction,” J. Hydraul. Eng., 130(2), pp. 140–148. [CrossRef]
Deshpande, V. , and Kumar, B. , 2015, “ Advent of Sheet Flow in Suction Affected Alluvial Channels,” Environ. Fluid Mech., 16(1), pp. 25–44. [CrossRef]
Jarvela, J. , 2004, “ Effect of Submerged Flexible Vegetation on Flow Structure and Resistance,” J. Hydrol., 307(1–4), pp. 233–241. [CrossRef]
Liu, D. , Diplas, P. , Fairbanks, J. D. , and Hodges, C. C. , 2008, “ An Experimental Study of Flow Through Rigid Vegetation,” J. Geophys. Res., 113(F4).
Huai, W. , Han, J. , Zeng, Y. , An, X. , and Qian, Z. , 2009, “ Velocity Distribution of Flow With Submerged Flexible Vegetations Based on Mixing-Length Approach,” Appl. Math. Mech., 30(3), pp. 343–351. [CrossRef]
Kouwen, N. , and Unny, T. E. , 1973, “ Flexible Roughness in Open Channels,” J. Hydraul. Div., Am. Soc. Civ. Eng., 99(5), pp. 713–728.
Okamoto, T. , and Nezu, I. , 2009, “ Turbulence Structure and ‘Monami’ Phenomena in Vegetated in Flexible Vegetated Open Channel Flows,” J. Hydraul. Res., 47(6), pp. 798–810. [CrossRef]
Okamoto, T. , and Nezu, I. , 2010, “ Flow Resistance in Open-Channel Flows With Rigid and Flexible Vegetation,” River Flow 2010, Karlsruhe: Bundesanstalt für Wasserbau, Braunschweig, Germany, pp. 261–268.
Goring, D. G. , and Nikora, V. I. , 2002, “ Despiking Acoustic Doppler Velocimeter Data,” J. Hydraul. Eng., 128(1), pp. 117–126. [CrossRef]
Dey, S. , Das, R. , Gaudio, R. , and Bose, S. K. , 2012, “ Turbulence in Mobile Bed Streams for Flat Bed,” Acta Geophys., 60(6), pp. 1547–1588. [CrossRef]
Dey, S. , and Nath, T. K. , 2010, “ Turbulence Characteristics in Flows Subjected to Boundary Injection and Suction,” J. Eng. Mech., 136(7), pp. 877–888. [CrossRef]
Cao, D. , and Chiew, Y.-M. , 2014, “ Suction Effects on Sediment Transport in Closed-Conduit Flows,” J. Hydraul. Eng., 140(5), p. 04014008-1-9. [CrossRef]
Chen, X. , and Chiew, Y.-M. , 2004, “ Velocity Distribution of Turbulent Open Channel Flow With Bed Suction,” J. Hydraul. Eng., 130(2), pp. 140–148. [CrossRef]
Lu, S. S. , and Willmarth, W. W. , 1973, “ Measurements of the Structure of the Reynolds Stress in a Turbulent Boundary Layer,” J. Fluid Mech., 60(3), pp. 481–511. [CrossRef]
Raupach, M. R. , 1981, “ Conditional Statistics of Reynolds Stress in Rough-Wall and Smooth-Wall Turbulent Boundary Layers,” J. Fluid Mech., 108, pp. 363–382. [CrossRef]
Nezu, I. , and Sanjou, M. , 2008, “ Turbulence Structure and Coherent Motion in Vegetated Canopy Open Channel Flows,” J. Hydro-Environ. Res., 2(2), pp. 62–90. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

Schematic diagram showing (a) experimental flume setup and (b) pattern of placing vegetation

Grahic Jump Location
Fig. 2

Velocity profiles of different vegetation pattern for no-seepage, 10% seepage, and 15% seepage cases (dashed lines show the top of the vegetation): (a) 5 mm upstream–10 mm downstream and (b) 10 mm upstream–5 mm downstream

Grahic Jump Location
Fig. 3

Reynolds stress profiles of different vegetation patterns for no-seepage, 10% seepage, and 15% seepage cases (dashed lines show the top of the vegetation): (a) 5 mm upstream–10 mm downstream and (b) 10 mm upstream–5 mm downstream

Grahic Jump Location
Fig. 4

Turbulent Intensities in streamwise direction, σu (+, ◊, ○) and vertical direction, σw (+,,•) for no-seepage, 10% seepage, and 15% seepage cases: (a) 5 mm upstream–10 mm downstream and (b) 10 mm upstream–5 mm downstream

Grahic Jump Location
Fig. 5

Profiles showing third-order moments of 5 mm diameter upstream–10 mm diameter downstream for no-seepage, 10% seepage, and 15% seepage: (a) upstream, (b) center, and (c) downstream

Grahic Jump Location
Fig. 6

Profiles showing third-order moments of 10 mm diameter upstream–5 mm diameter downstream for no-seepage, 10% seepage, and 15% seepage: (a) upstream, (b) center, and (c) downstream

Grahic Jump Location
Fig. 7

Profiles showing fractional stress contribution to Reynolds stress of 5 mm diameter upstream and 10 mm diameter downstream: (a) upstream, (b) center, and (c) downstream

Grahic Jump Location
Fig. 8

Profiles showing fractional stress contribution to Reynolds stress of 10 mm diameter upstream and 5 mm diameter downstream: (a) upstream, (b) center, and (c) downstream

Grahic Jump Location
Fig. 9

Drag coefficient of different vegetation pattern (a)–(d) and average CD (e) for no-seepage, 10% seepage and 15% seepage

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In