Turbulence in Plant Canopies

Annual Review of Fluid Mechanics - Tập 32 Số 1 - Trang 519-571 - 2000
John Finnigan1
1CSIRO Land and Water, F.C. Pye Laboratory, Canberra, Australia

Tóm tắt

▪ Abstract  The single-point statistics of turbulence in the ‘roughness sub-layer’ occupied by the plant canopy and the air layer just above it differ significantly from those in the surface layer. The mean velocity profile is inflected, second moments are strongly inhomogeneous with height, skewnesses are large, and second-moment budgets are far from local equilibrium. Velocity moments scale with single length and time scales throughout the layer rather than depending on height. Large coherent structures control turbulence dynamics. Sweeps rather than ejections dominate eddy fluxes and a typical large eddy consists of a pair of counter-rotating streamwise vortices, the downdraft between the vortex pair generating the sweep. Comparison with the statistics and instability modes of the plane mixing layer shows that the latter rather than the boundary layer is the appropriate model for canopy flow and that the dominant large eddies are the result of an inviscid instability of the inflected mean velocity profile. Aerodynamic drag on the foliage is the cause both of the unstable inflected velocity profile and of a ‘spectral short cut’ mechanism that removes energy from large eddies and diverts it to fine scales, where it is rapidly dissipated, bypassing the inertial eddy-cascade. Total dissipation rates are very large in the canopy as a result of the fine-scale shear layers that develop around the foliage.

Từ khóa


Tài liệu tham khảo

10.1175/1520-0450(1968)007<0073:TAWSSW>2.0.CO;2

Amiro BD. 1990. Drag coefficients and turbulence spectra within three boreal forest canopies,Boundary-Layer Meteorol.52:227–46

10.1146/annurev.fl.13.010181.001023

10.1023/A:1001722609229

10.1007/BF00120814

10.1007/BF00121712

10.1016/S0168-1923(97)00072-5

Batchelor GK. 1959.The Theory of Homogeneous Turbulence.London: Cambridge Univ. Press

Bergström H, Högström U. 1989. Turbulent exchange above a pine forest. II. Organized structures.Boundary-Layer Meteorol.49:231–63

10.1017/S0022112080002807

10.1017/S002211207400190X

Brunet Y, Finnigan JJ, Raupach MR. 1994. A wind tunnel study of air flow in waving wheat: single-point velocity statistics.Boundary-Layer Meteorol.70:95–132

1981, Annu. Rev. Fluid Mech., 13, 437

Collineau S, Brunet Y. 1993. Detection of turbulent coherent motions in a forest canopy, Part II: Timescales and conditional averages.Boundary-Layer Meteorol.66:49–73

10.1063/1.858334

Coppin PA, Raupach MR, Legg BJ. 1986. Experiments on scalar dispersion within a model plant canopy. II. An elevated plane source.Boundary-Layer Meteorol.35:167–91

Corrsin S. 1974. Limitations of gradient transport models in random walks and turbulence.Adv. Geophys.18A:25–60

Denmead OT, Bradley EF. 1985. Flux-gradient relationships in a forest canopy. InThe Forest-Atmosphere Interaction,ed. BA Hutchison, BB Hicks, pp. 421–42. Dordrecht, The Netherlands: Reidel

1987, Irrig. Sci., 8, 131

Dimotakis PE, Brown GL. 1976. The mixing layer at high Reynolds number: large structure dynamics and entrainment.J. Fluid Mech.78:535–60

Drazin PG, Reid WH. 1981.Hydrodynamic Stability.Cambridge, UK: Cambridge Univ. Press. 527 pp.

10.1023/A:1000301303543

Finnigan, JJ. 1979. Turbulence in waving wheat II. Structure of momentum transfer.Boundary-Layer Meteorol.16:213–36

Finnigan JJ. 1985. Turbulent transport in flexible plant canopies. InThe Forest-Atmosphere Interaction,ed. BA Hutchison, BB Hicks, pp. 443–80. Dordrecht, The Netherlands: Reidel

Finnigan JJ, Brunet Y. 1995. Turbulent airflow in forests on flat and hilly terrain. InWind and Trees,ed. MP Coutts, J Grace, pp. 3–40. Cambridge, UK: Cambridge Univ. Press

Finnigan JJ, Raupach MR. 1987. Transfer processes in plant canopies in relation to stomatal characteristics. InStomatal Function,ed. E Zeiger, GD Farquar, IR Cowan, pp. 385–429. Stanford, CA: Stanford Univ. Press. 503 pp.

Finnigan JJ, Shaw RH. 2000. A wind tunnel study of airflow in waving wheat: an Empirical Orthogonal Function analysis of the large-eddy motion.Boundary-Layer Meteorol.In press

10.1007/BF00122339

Gardiner BA. 1994. Wind and wind forces in a plantation spruce forest.Boundary-Layer Meteorol.67:161–86

Garratt JR. 1992.The Atmospheric Boundary Layer.Cambridge, UK: Cambridge Univ. Press. 316 pp.

10.1023/A:1000453031036

Judd MJ, Raupach MR, Finnigan JJ. 1996. A wind tunnel study of turbulent flow around single and multiple windbreaks, Part one: Velocity fields.Boundary-Layer Meteorol.80:127–65

Kaimal JC, Finnigan JJ. 1994.Atmospheric Boundary Layer Flows: Their Structure and Measurement.New York: Oxford Univ. Press. 289 pp.

Kruijt B, Klaassan W, Hutjes RWA. 1995. Adjustment of turbulent momentum flux over forest downwind of an edge. InWind and Trees,ed. MP Coutts, J Grace. Cambridge, UK: Cambridge Univ. Press. 485 pp.

10.1175/1520-0450(1990)029<0916:TIOASO>2.0.CO;2

10.1002/qj.49712454904

Lee X, Black TA. 1993. Atmospheric turbulence within and above a Douglas Fir stand. Part II: Eddy fluxes of sensible heat and water vapor.Boundary-Layer Meteorol.64:369–89

Leonard A. 1974. Energy cascade in large-eddy simulations of turbulent fluid flows.Adv. Geophys.18A:237–48

10.1017/S0022112073000315

10.1007/BF00713294

10.1175/1520-0469(1964)021<0099:TSONIT>2.0.CO;2

Lumley JL. 1967. The structure of inhomogeneous turbulent flows. InAtmospheric Turbulence and Radio Wave Propagation,ed. AM Yaglom, VI Tatarsky, pp. 166. Moscow: Nauka

Lumley JL. 1981. Coherent structures in turbulence. InTransition and Turbulence,ed. RE Meyer, pp. 215–41. Mathematics Research Center Symposia and Advanced Seminar Series. New York: Academic

10.1007/BF00137035

10.1007/BF00122091

10.1016/0168-1923(91)90058-X

10.1017/S0022112064000908

10.1017/S0022112065001520

10.1017/S0022112089000741

Novak MD, Warland JS, Orchansky AL, Ketler R, Green S. 2000. Comparison between wind tunnel and field measurements of turbulent flow. Part 1: Uniformly thinned forests.Boundary-Layer Meteorol.In press

10.1063/1.1761356

10.1023/A:1000945626163

Paw U KT, Brunet Y, Collineau S, Shaw RH, Maitani T, et al. 1992. On coherent structures in turbulence above and within agricultural plant canopies.Agric. For. Meteorol.61:55–68. (Corrigendum:Agric. For. Meteorol.63:127)

10.1017/S0022112081000529

10.1098/rstb.1989.0043

10.1115/1.3119492

Raupach MR, Coppin PA, Legg BJ. 1986. Experiments on scalar dispersion within a model plant canopy. Part I: The turbulence structure.Boundary-Layer Meteorol.35:21–52

Raupach MR, Finnigan JJ, Brunet Y. 1989. Coherent eddies in vegetation canopies.Proc. Australasian Conf. Heat Mass Transfer, 4th,May 9–12, Christchurch, New Zealand, pp. 75–90.

Raupach MR, Finnigan JJ, Brunet Y. 1996. Coherent eddies and turbulence in vegetation canopies: the mixing layer analogy.Boundary-Layer Meteorol.78:351–82

Raupach MR, Shaw RH. 1982, Averaging procedures for flow within vegetation canopies.Boundary-Layer Meteorol.22:79–90

10.1146/annurev.fl.13.010181.000525

10.1146/annurev.fl.23.010191.003125

Rogers MM, Moser RD. 1992. The three-dimensional evolution of a plane mixing layer: the Kelvin-Helmholtz rollup.J. Fluid Mech.243:183–226

10.1017/S0022112094001370

10.1007/BF00121891

10.1007/BF00225863

Shaw RH. 1977. The influence of vegetation on canopy flow. InProc. 13thAm. Meteorol. Soc. Conf. on Agric. and For. Meteorol.pp. 9–10. Purdue Univ., Indiana

Shaw RH, Brunet Y, Finnigan JJ, Raupach MR. 1995. A wind tunnel study of air flow in waving wheat: two-point velocity statistics.Boundary-Layer Meteorol.76:349–76

10.1007/BF00124010

10.1016/0168-1923(89)90091-9

10.1007/BF00120528

10.1007/BF02033994

Shaw RH, Seginer I. 1985. The dissipation of turbulence in plant canopies. Extended abstract: Am. Meteorol. Soc. 7thSymp. on Turbulence and Diffusion Abstracts,pp 200–3.

10.1007/BF00123490

10.1175/1520-0450(1983)022<1922:SOTRSI>2.0.CO;2

1992, Boundary-Layer Meteorol., 58, 173

10.1017/S0022112078000294

10.1023/A:1001108411184

10.1002/qj.49709439906

Townsend AA. 1976.The Structure of Turbulent Shear Flow.Cambridge, UK: Cambridge Univ. Press. 429 pp.

10.1007/BF00121591

10.1007/BF00120736

1977, J. Appl. Meteorol., 16, 1198

Winant CD, Browand FK. 1974. Vortex pairing: the mechanism of turbulent mixing layer growth at moderate Reynolds number.J. Fluid Mech.63:237–55

10.1175/1520-0450(1994)033<0704:PFDCMA>2.0.CO;2

Thông tin
Thông tin xuất bản

Annual Review of Fluid Mechanics

Tập 32 Số 1

519-571

Thông tin tác giả