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Influence of collective boulder array on the surrounding time-averaged and turbulent flow fields

  • Special topics from the 35th IAHR World Congress
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Abstract

Arrays of large immobile boulders, which are often encountered in steep mountain streams, affect the timing and magnitude of sediment transport events through their interactions with the approach flow. Despite their importance in the quantification of the bedload rate, the collective influence of a boulder array on the approach time-averaged and turbulent flow field has to date been overlooked. The overarching objective is, thus, to assess the collective effects of a boulder array on the time-averaged and turbulent flow fields surrounding an individual boulder within the array, placing particular emphasis on highlighting the bed shear stress spatial variability. The objective of this study is pursued by resolving and comparing the time-averaged and turbulent flow fields developing around a boulder, with and without an array of isolated boulders being present. The results show that the effects of an individual boulder on the time-averaged streamwise velocity and turbulence intensity were limited to the boulder’s immediate vicinity in the streamwise (x/d c < 2–3) and vertical (z/d c < 1) directions. Outside of the boulder’s immediate vicinity, the time-averaged streamwise velocity was found to be globally decelerated. This global deceleration was attributed to the form drag generated collectively by the boulder array. More importantly, the boulder array reduced the applied shear stress exerted on the individual boulders found within the array, by absorbing a portion of the total applied shear. Furthermore, the array was found to have a “homogenizing” effect on the near-bed turbulence thus significantly reducing the turbulence intensity in the near-bed region. The findings of this study suggest that the collective boulder array bears a portion of the total applied bed shear stress as form drag, hence reducing the available bed shear stress for transporting incoming mobile sediment. Thus, the effects of the boulder array should not be ignored in sediment transport predictions. These effects are encapsulated in this study by Equation (6).

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References

  • Afzalimehr H, Anctil F (2000) Accelerating shear velocity in gravel-bed channels. Hydrological Science Journal 45: 113–123.

    Article  Google Scholar 

  • Bathurst JC (1987) Critical conditions for bed material movement in steep, boulder-bed streams. In: Beschta RL et al. (eds.), Erosion and Sedimentation in the Pacific Rim. IAHS Publication No. 165, Wallingford, UK. pp 309–318.

    Google Scholar 

  • Best JL (1993) On the interactions between turbulent flow structure, sediment transport and bedform development: Some considerations from recent experimental research. In: Clifford NJ et al. (Eds.), Turbulence: Perspectives on Flow and Sediment Transport. Wiley, Chichester, UK. pp 61–92.

    Google Scholar 

  • Dey S, Sarkar S, Bose SK, et al. (2011) Wall-wake flows downstream of a sphere placed on a plane rough-wall. Journal of Hydraulic Engineering 137(10): 1173–1189. DOI: 10.1061/(ASCE)0733-9429(2007)133:3(288).

    Article  Google Scholar 

  • Ferro V (2003) ADV measurements of velocity distributions in a gravel-bed flume. Earth Surface Processes and Landforms 28(7): 707–722.

    Article  Google Scholar 

  • Hinze JO (1975) Turbulence. McGraw-Hill, New York, NY, USA.

    Google Scholar 

  • Kironoto BA, Graf WH (1994) Turbulence characteristics in rough uniform open-channel flow. Proceedings of the Institute of Civil Engineering — Water Maritime and Energy 106(4): 333–344.

    Article  Google Scholar 

  • Lacey RWJ, Roy AG (2008) Fine-scale characterization of the turbulent shear layer of an instream pebble cluster. Journal of Hydraulic Engineering 134(7): 925–936. DOI: 10.1061/(ASCE)0733-9429/2008/7-925-936.

    Article  Google Scholar 

  • Nezu I, Nakagawa H (1993) Turbulence in open-channel flows. Balkema, Rotterdam, The Netherlands.

    Google Scholar 

  • Morris HM (1955) Flow in rough conditions. Transactions of the American Society of Civil Engineers 120: 373–398.

    Google Scholar 

  • Papanicolaou AN, Kramer CM (2005) The role of relative submergence on cluster microtopography and bedload predictions on mountain streams. In: Parker G, Garcia MH (eds.), Proceedings of the International Symposium “River Coastal and Estuarine Morphodynamics”, 4-7 October 2005, Urbana, IL, USA Taylor and Francis, Philadelphia, PA, USA.

    Google Scholar 

  • Papanicolaou AN, Evangelopoulos N, Diplas P, et al. (2002) Stochastic incipient motion criterion for spheres under various bed packing conditions. Journal of Hydraulic Engineering 128: 369–380.

    Article  Google Scholar 

  • Papanicolaou AN, Dermisis D, Elhakeem M (2011) Investigating the role of clasts on the movement of sand in gravel bed rivers. Journal of Hydraulic Engineering 137(9): 871–883.

    Article  Google Scholar 

  • Papanicolaou AN, Kramer CM, Tsakiris AG, et al. (2012) Effects of a fully submerged boulder within a boulder array on the mean and turbulent flow fields: Implications to bedload transport. Acta Geophysica. DOI: 10.2478/s11600-012-0044-6.

    Google Scholar 

  • Pitlick J, Mueller ER, Segura C, et al. (2005) Relation between flow, surface-layer armoring and sediment transport in gravel-bed rivers. Earth Surface Processes and Landforms 33: 1192–1209. DOI: 10.1002/esp.1607.

    Article  Google Scholar 

  • Recking A, Frey P, Paquier A, et al. (2008) Feedback between bed load transport and flow resistance in gravel and cobble bed rivers. Water Resources Research 44: W05412. DOI: 10.1029/2007WR006219.

    Google Scholar 

  • Rickenmann, D (2001) Comparison of bedload transport in torrents and gravel bed streams. Water Resources Research 37: 3295–3305.

    Article  Google Scholar 

  • SonTek (2001) ADV operation manual. SonTek Inc., San Diego, CA, USA.

    Google Scholar 

  • Strom KB, Papanicolaou AN (2007) ADV measurements around a cluster microform in a shallow mountain stream. Journal of Hydraulic Engineering 133(12): 1379–1389. DOI: 10.1061/(ASCE)0733-9429(2007)133:12(1379).

    Article  Google Scholar 

  • Voulgaris G, Trowbridge JH (1997) Evaluation of the Acoustic Doppler Velocimeter (ADV) for turbulence measurements. Journal of Atmospheric and Oceanic Technology 15: 272–289.

    Article  Google Scholar 

  • Yager EM, Kirchner JW, Dietrich WE (2007) Calculating bedload transport in steep boulder bed channels. Water Resources Research 43: W07418. DOI: 10.1029/2006WR005432.

    Article  Google Scholar 

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Authors and Affiliations

  1. IIHR-Hydroscience & Engineering, The University of Iowa, Iowa City, IA, 52246-1585, USA

    Achilleas G. Tsakiris & James H. J. Buchholz

  2. Department of Civil and Environmental Engineering, The University of Tennessee at Knoxville, 412 John D. Tickle Building, Knoxville, TN, 37996, USA

    A. N. Thanos Papanicolaou

  3. South Florida Water Management District, West Palm Beach, FL, 33416, USA

    Seyed M. Hajimirzaie

Authors
  1. Achilleas G. Tsakiris
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  2. A. N. Thanos Papanicolaou
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  3. Seyed M. Hajimirzaie
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  4. James H. J. Buchholz
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Correspondence to A. N. Thanos Papanicolaou.

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Tsakiris, A.G., Papanicolaou, A.N.T., Hajimirzaie, S.M. et al. Influence of collective boulder array on the surrounding time-averaged and turbulent flow fields. J. Mt. Sci. 11, 1420–1428 (2014). https://doi.org/10.1007/s11629-014-3055-8

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  • DOI: https://doi.org/10.1007/s11629-014-3055-8

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