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Flume Experiments on Turbulent Flows Across Gaps of Permeable and Impermeable Boundaries

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Abstract

Laser Doppler anemometery and laser-induced fluorescence techniques were used to explore the spatial structure of the flow within and above finite cavities created within porous and solid media. The cavities within these two configurations were identical in size and were intended to mimic flow disturbances created by finite gaps and forest clearing. Because flows over permeable boundaries differ from their solid counterparts, the study here addresses how these differences in boundary conditions produce differences in, (i) bulk flow properties including the mean vorticity within and adjacent to the gaps, (ii) second-order statistics such as the standard deviations and turbulent stresses, (iii) the relative importance of advective to turbulent stress terms across various regions within and above the gaps, and (iv) the local imbalance between ejections and sweeps and momentum transport efficiencies of updrafts and downdrafts. Both configurations exhibited a primary recirculation zone of comparable dimensions inside the gap. The mean vorticity spawned at the upstream corner of the gap was more intense for the solid configuration when compared to its porous counterpart. The free-shear layer spawned from the upstream corner-edge deeper into the gap for the porous configuration. The momentum flux at the interface within and above the gap was enhanced by a factor of 1.5–2.0 over its upstream value, and this enhancement zone was much broader in size for the porous configuration. For the turbulent transport terms in the longitudinal and vertical mean momentum balances, these transport terms were significant inside the gap for both boundary configurations when compared to their upstream counterpart. The effectiveness of using incomplete cumulant expansion methods to describe the momentum transport efficiencies, and the relative contributions of ejections and sweeps to turbulent stresses, especially in this zone, were also demonstrated. The flatness factor for both velocity components, often used as a measure of intermittency, was highest in the vicinity of the upstream corner in both configurations. However, immediately following the downstream corner, the flatness factor remained large for the porous configuration, in contrast to its solid configuration counterpart.

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References

  • Antonia RA (1981) Conditional sampling in turbulence measurements. Annu Rev Fluid Mech 13: 131–156

    Article  Google Scholar 

  • Albertson JD, Parlange MB (1999) Surface length scales and shear stress: implications for land–atmosphere interaction over complex terrain. Water Resour Res 35: 2121–2132

    Article  Google Scholar 

  • Ashcroft G, Zhang X (2005) Vortical structures over rectangular cavities at low speed. Phys Fluids 17: 015104-1–015104-8

    Article  Google Scholar 

  • Batchelor GK, Townsend AA (1949) The nature of turbulent motion at large wavenumbers. Proc R Soc A 199: 238–255

    Article  Google Scholar 

  • Belcher SE, Jerram N, Hunt JCR (2003) Adjustment of a turbulent boundary layer to a canopy of roughness elements. J Fluid Mech 488: 369–398

    Article  Google Scholar 

  • Cassiani M, Katul GG, Albertson JD (2008) The effects of canopy leaf area index on airflow across forest edges: large-eddy simulation and analytical results. Boundary-Layer Meteorol 126: 433–460

    Article  Google Scholar 

  • Cava D, Katul GG, Scremieri A, Poggi D, Cescatti A, Giostra U (2006) Buoyancy and the sensible heat flux budget within a dense canopy. Boundary-Layer Meteorol 118: 217–240

    Article  Google Scholar 

  • Detto M, Katul GG, Siqueira MB, Juang JY, Stoy P (2008) The structure of turbulence near a tall forest edge: the backward facing step flow analogy revisited. Ecol Appl 18: 1420–1435

    Article  Google Scholar 

  • Dupont S, Brunet Y (2008) Edge flow and canopy structure: a large-eddy simulation study. Boundary-Layer Meteorol 126: 51–71

    Article  Google Scholar 

  • Durst F, Jovanovic J, Johansson TG (1992) On the statistical proprieties of truncated Gram-Charlier series expansions in turbulent wall-bounded flows. Phys Fluids A 4(1): 118–126

    Article  Google Scholar 

  • Fer I, McPhee MG, Sirevaag A (2004) Conditional statistics of the Reynolds Stress in the under-ice boundary layer. Geophys Res Lett 31: 2004GL020475

    Article  Google Scholar 

  • Finnigan J (2000) Turbulence in plant canopies. Annu Rev Fluid Mech 32: 519–571

    Article  Google Scholar 

  • Frenkiel F, Klebanoff P (1967) Higher order correlations in a turbulent field. Phys Fluids 10: 507–522

    Article  Google Scholar 

  • Irvine MR, Gardiner BA, Hill MK (1997) The evolution of turbulence across a forest edge. Boundary-Layer Meteorol 84: 467–496

    Article  Google Scholar 

  • Katul GG, Hsieh CI, Kuhn G, Ellsworth D, Nie D (1997) The turbulent eddy motion at the forest–atmosphere interface. J Geophys Res 102: 13409–13421

    Article  Google Scholar 

  • Katul GG, Geron CD, Hsieh CI, Vidakovic B, Guenther AB (1998) Active turbulence and scalar transport near the land–atmosphere interface. J Appl Meteorol 37: 1533–1546

    Article  Google Scholar 

  • Katul GG, Poggi D, Cava D, Finnigan D (2006) The relative importance of ejections and sweeps to momentum transfer in the atmospheric boundary layer. Boundary-Layer Meteorol 120: 367–375

    Article  Google Scholar 

  • Klaassen W (1992) Average fluxes from heterogeneous vegetated regions. Boundary-Layer Meteorol 58: 329–354

    Article  Google Scholar 

  • Laurence W (2004) Forest climate interactions in fragmented tropical landscapes. Philos Trans R Soc Lond 359: 345–352

    Article  Google Scholar 

  • Li D, Bou-Zeid E (2011) Stability effects on turbulent coherent structures and transport efficiency in the atmospheric surface layer. Boundary-Layer Meteorol 140(2): 243–262

    Article  Google Scholar 

  • Manes C., Poggi D., Ridolfi L. (2011) Turbulent boundary layers over permeable walls: scaling and near-wall structure. J Fluid Mech 687: 141–170

    Article  Google Scholar 

  • Nakagawa H, Nezu I (1977) Prediction of the Reynolds stress from bursting events in open-channel flows. J Fluid Mech 80: 99–128

    Article  Google Scholar 

  • Poggi D, Porporato A, Ridolfi L (2002) An experimental contribution to near-wall measurements by means of a special laser Doppler anemometry technique. Exp Fluids 32: 366–375

    Article  Google Scholar 

  • Poggi D, Katul GG, Albertson JD (2004) Momentum transfer and turbulent kinetic energy budgets within a dense model canopy. Boundary-Layer Meteorol 111: 589–614

    Article  Google Scholar 

  • Poggi D, Katul GG, Albertson JD (2006) Scalar dispersion within a model canopy: measurements and three-dimensional Lagrangian models. Adv Water Resour 29: 326–335

    Article  Google Scholar 

  • Poggi D, Katul GG, Vidakovic B (2011) The role of wake production on the scaling laws of scalar concentration fluctuation spectra inside dense canopies. Boundary-Layer Meteorol 139: 83–95

    Article  Google Scholar 

  • Pope SB (2000) Turbulent flows. Cambridge University Press, UK, 771 pp

  • Raupach MR (1981) Conditional statistics of Reynolds stress in rough-wall and smooth-wall turbulent boundary layers. J Fluid Mech 108: 363–382

    Article  Google Scholar 

  • Raupach MR, Finnigan JJ, Brunet Y (1996) Coherent eddies and turbulence in vegetation canopies: the mixing layer analogy. Boundary-Layer Meteorol 78: 351–382

    Article  Google Scholar 

  • Sandborn VA (1959) Measurements of intermittency of turbulent motion in a boundary layer. J Fluid Mech 6: 221–240

    Article  Google Scholar 

  • Schlegel F, Stiller J, Bienert A, Maas HG, Queck R, Bernhofer C (2012) Large-eddy simulation of inhomogeneous canopy flows using high resolution terrestrial laser scanning data. Boundary-Layer Meteorol 142: 223–243

    Article  Google Scholar 

  • Seraphin A, Guyenne P (2008) A flume experiment on the adjustment of the mean and turbulent statistics to a transition from short to tall sparse canopies. Boundary-Layer Meteorol 129: 47–64

    Article  Google Scholar 

  • Simpson RL (1989) Turbulent boundary layer separation. Annu Rev Fluid Mech 21: 3808–3818

    Article  Google Scholar 

  • Spazzini PG, Iuso G, Onorato M, Zurlo N, Di Cicca GM (2001) Unsteady behavior of back-facing step flow. Exp Fluids 30: 551–561

    Article  Google Scholar 

  • Thomas KF, Wilson JD (1999) Wind and remnant tree sway in forest cutblocks. I. Measured winds in experimental cutblocks. Agric For Meteorol 93: 229–242

    Article  Google Scholar 

  • Veen WL, Klaassen W, Kruijt B, Hutjes RWA (1996) Forest edges and the soil–vegetation–atmosphere interaction at the landscape scale: the state of affairs. Prog Phys Geogr 20: 292–310

    Article  Google Scholar 

  • Wyngaard JC, Moeng CH (1992) Parameterizing turbulent diffusion through the joint probability density. Boundary-Layer Meteorol 60: 1–13

    Article  Google Scholar 

  • Yang B, Raupach MR, Shaw RH, Tha K, Paw U, Morse AP (2006a) Large-eddy simulation of turbulent flow across a forest edge. Part I: flow statistics. Boundary-Layer Meteorol 120: 377–412

    Article  Google Scholar 

  • Yang B, Morse AP, Shaw RH, Tha K, Paw U (2006b) Large-eddy simulation of turbulent flow across a forest edge. Part II: momentum and turbulent kinetic energy budgets. Boundary-Layer Meteorol 121: 433–457

    Article  Google Scholar 

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Authors and Affiliations

  1. Dipartimento di Ingegneria dell’Ambiente, del Territorio e delle Infrastrutture, Politecnico di Torino, Torino, Italy

    S. Fontan, D. Poggi & L. Ridolfi

  2. Nicholas School of the Environment, Duke University, Durham, NC, USA

    G. G. Katul

  3. Department of Civil and Environmental Engineering, Duke University, Durham, NC, USA

    G. G. Katul

  4. Department of Engineering and the Environment, Energy and Climate Change Research Group, University of Southampton, Southampton, SO17 1RJ, UK

    C. Manes

Authors
  1. S. Fontan
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  2. G. G. Katul
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  3. D. Poggi
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  4. C. Manes
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  5. L. Ridolfi
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Correspondence to S. Fontan.

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Fontan, S., Katul, G.G., Poggi, D. et al. Flume Experiments on Turbulent Flows Across Gaps of Permeable and Impermeable Boundaries. Boundary-Layer Meteorol 147, 21–39 (2013). https://doi.org/10.1007/s10546-012-9772-z

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  • DOI: https://doi.org/10.1007/s10546-012-9772-z

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