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Wind Field Coherence And Dynamic Wind Forces

  • S. Krenk
Part of the Solid Mechanics and its Applications book series (SMIA, volume 47)

Abstract

Dynamic response of structures to turbulent wind depends on the temporal and spatial fluctuations of the wind. In principle the statistical properties could be combined into a random field model of the turbulent wind. However, in practice it turns out to be very difficult to combine the height variation of the mean wind with a fully satisfactory stochastic description of the turbulent fluctuations. Several models have been proposed, but none of them combine completeness and simplicity, and we shall restrict the attention to some basic characteristics. The combination of spatial and temporal fluctuations is made by Taylor’s hypothesis of convected frozen turbulence. This amounts to convecting a time-invariant velocity field downstream with the mean velocity. Within this approximation the problem is reduced to a stochastic spatial wind velocity field. The classical account of the theory for homogeneous isotropic turbulence is Batchelor (1953). Several extensions to anisotropic turbulence have been proposed. The most promising is probably that of Mann (1994), in which the effect of shear due to the vertical gradient of the mean wind is accounted for as a perturbation in the Navier-Stokes equations. This model accounts for differences in the three velocity components and is easily adapted to simulation, Mann fc Krenk (1993).

Keywords

Exponential Format Coherence Function Wind Force Convect Turbulence Homogeneous Isotropic Turbulence 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • S. Krenk
    • 1
  1. 1.Division of MechanicsLund Institute of Technology Lund UniversityLundSweden

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