PIV measurement of buffer and logarithmic layers with detached eddies which mimics the neutral atmospheric surface layer

Authors

  • Yasuo Hattori Central Research Institute of Electric Power Industry, Japan
  • Hitoshi Suto Central Research Institute of Electric Power Industry, Japan
  • Keisuke Nakao Central Research Institute of Electric Power Industry, Japan
  • Hiromaru Hirakuchi Central Research Institute of Electric Power Industry, Japan

DOI:

https://doi.org/10.18409/ispiv.v1i1.141

Keywords:

Turbulence, Boundary layer flow, Atmospheric surface layer, Coherence structure, Organized motion

Abstract

Accurate comprehension of turbulence characteristics in the atmospheric surface layer (ASL) under near neutral conditions, which is a lower part of the atmospheric boundary layer and a very high-Re number flow, is critically required in view of the increasing and broadening use of numerical weather prediction models. The models need to estimate turbulence fluxes of momentum, heat and moisture in the ASL as boundary conditions. On the other hand, observations (Högström 1990, Drobinski et al. 2007) have revealed that the fluxes under near-neutral conditions are often inconsistent with Monin-Obukhof theory, which has been widely used in models. The observations were conducted over flat surfaces with homogeneous roughness, and thus the violation from the theory might not be due to the underlying surface conditions. Thus, aiming to investigate an origin of the violation from the theory, we have carried out a wind tunnel experiment on the logarithmic layer along a smooth flat wall with a larger-scale disturbance, which mimics the near-neutral atmospheric surface layer (Hattori et al. 2010). In the present study, we especially examine a PIV measurement with a long-distance microscope lens to discuss the interaction of turbulences structures between buffer and logarithmic layers, which must give a clue on Reynolds number effects

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Published

2021-08-01

Issue

Section

Boundary Layers