Large-eddy simulation of turbulent flow across a forest edge. Part II: Momentum and turbulent kinetic energy budgets

被引:63
|
作者
Yang, Bai
Morse, Andrew P.
Shaw, Roger H.
Paw U, Kyaw Tha
机构
[1] Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA
[2] Univ Calif Davis, Dept Land Air & Water Resources, Davis, CA USA
[3] Univ Liverpool, Dept Geog, Liverpool L69 3BX, Merseyside, England
基金
美国国家科学基金会;
关键词
forest edge; large-eddy simulation; momentum budget; turbulent kinetic energy budget;
D O I
10.1007/s10546-006-9083-3
中图分类号
P4 [大气科学(气象学)];
学科分类号
0706 ; 070601 ;
摘要
Momentum and turbulent kinetic energy (TKE) budgets across a forest edge have been investigated using large-eddy simulation (LES). Edge effects are observed in the rapid variation of a number of budget terms across this vegetation transition. The enhanced drag force at the forest edge is largely balanced by the pressure gradient force and by streamwise advection of upstream momentum, while vertical turbulent diffusion is relatively insignificant. For variance and TKE budgets, the most important processes at the forest edge are production due to the convergence (or divergence) of the mean flow, streamwise advection, pressure diffusion and enhanced dissipation by canopy drag. Turbulent diffusion, pressure redistribution and vertical shear production, which are characteristic processes in homogeneous canopy flow, are less important at the forest transition. We demonstrate that, in the equilibrated canopy flow, a substantial amount of TKE produced in the streamwise direction by the vertical shear of the mean flow is redistributed in the vertical direction by pressure fluctuations. This redistribution process occurs in the upper canopy layers. Part of the TKE in the vertical velocity component is transferred by turbulent and pressure diffusion to the lower canopy levels, where pressure redistribution takes place again and feeds TKE back to the streamwise direction. In this TKE cycle, the primary source terms are vertical shear production for streamwise velocity variance and pressure redistribution for vertical velocity variance. The evolution of these primary source terms downwind of the forest edge largely controls the adjustment rates of velocity variances.
引用
收藏
页码:433 / 457
页数:25
相关论文
共 50 条
  • [41] Large-eddy simulation of a turbulent forced plume
    Zhou, X
    Luo, KH
    Williams, JJR
    [J]. EUROPEAN JOURNAL OF MECHANICS B-FLUIDS, 2001, 20 (02) : 233 - 254
  • [42] LARGE-EDDY SIMULATION OF A TURBULENT REACTING PLUME
    SYKES, RI
    HENN, DS
    PARKER, SF
    LEWELLEN, WS
    [J]. ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS, 1992, 26 (14): : 2565 - 2574
  • [43] LARGE-EDDY SIMULATION OF TURBULENT ANISOCHORIC FLOWS
    FUREBY, C
    [J]. AIAA JOURNAL, 1995, 33 (07) : 1263 - 1272
  • [44] Large-eddy simulation of premixed turbulent combustion
    Pitsch, H
    de Lageneste, LD
    [J]. COMPUTATIONAL FLUID AND SOLID MECHANICS 2003, VOLS 1 AND 2, PROCEEDINGS, 2003, : 1096 - 1099
  • [45] Large eddy simulation of SGS turbulent kinetic energy and SGS turbulent dissipation in a backward-facing step turbulent flow
    Wang, B
    Zhang, HQ
    Wang, XL
    [J]. CHINESE PHYSICS LETTERS, 2004, 21 (09) : 1773 - 1776
  • [46] A Large-Eddy Simulation Study of Turbulent Flow Over Multiscale Topography
    Feng Wan
    Fernando Porté-Agel
    [J]. Boundary-Layer Meteorology, 2011, 141 : 201 - 217
  • [47] Large-eddy simulation of supersonic turbulent flow in axisymmetric nozzles and diffusers
    Ghosh, Somnath
    Sesterhenn, Joern
    Friedrich, Rainer
    [J]. INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW, 2008, 29 (03) : 579 - 590
  • [48] Constrained large-eddy simulation of turbulent flow over rough walls
    Zhang, Wen
    Wan, Minping
    Xia, Zhenhua
    Wang, Jianchun
    Lu, Xiyun
    Chen, Shiyi
    [J]. PHYSICAL REVIEW FLUIDS, 2021, 6 (04)
  • [49] LARGE-EDDY SIMULATION OF TURBULENT FLOW WITH HEAT TRANSFER IN A ROD BUNDLE
    Tzanos, Constantine P.
    Popov, Maxim
    [J]. NUCLEAR TECHNOLOGY, 2013, 181 (03) : 466 - 478
  • [50] Large-eddy simulation of suspended sediment transport in turbulent channel flow
    ZHU Hai
    WANG Ling-ling
    TANG Hong-wu
    [J]. Journal of Hydrodynamics, 2013, 25 (01) : 48 - 55