Characterizing Coherent Wind Structures using Large-Scale Particle Tracking Velocimetry: A Proof-of-Principle Study

The Science of Making Torque from Wind 2012

Rosi, G.A.^1 ; La Bastide, B.^1 ; Gaebler, J.^1,2 ; Kinzel, M.^3 ; Rival, D.E.^1

Department of Mechanical Engineering, University of Calgary, 2500 University Dr. NW, Calgary

AB, Canada^1

Department of Mechanical Engineering, Technische Universitaet Berlin, 135 Strasse des 17. Juni, Berlin, Germany^2

GALCIT, California Institute of Technology, 1200 E California Blvd., Pasadena, United States^3

关键词: Particle tracking velocimetry;    Proof of principles;    Spanwise vortex;    Standard deviation;    Stream-wise velocities;    Turbulent boundary layers;    Velocity profiles;    Vortex distribution;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/555/1/012085/pdf
DOI  :  10.1088/1742-6596/555/1/012085

来源: IOP

【 摘 要 】

The following study proposes a two-dimensional large-scale particle tracking velocimetry (LS-PTV) system to characterize coherent wind structures. Seven minutes of LS-PTV data is collected via an apparatus that seeds fog-filled soap bubbles into the wind at a height of 6m from the ground. The LS-PTV data is compared to 20 minutes of data collected concurrently from a wind mast at the same site. The LS-PTV system recorded a mean streamwise velocity of 1.35m/s with a standard deviation of 0.23m/s at a mean height of 2.50m with a standard deviation of 0.7m, which agrees well with the velocity profile measured by the wind mast. Furthermore, the Reynolds stresses measured by the LS-PTV system are found to compare to those measured by the wind mast and by Klebanoff [1] for a canonical turbulent boundary layer. The current study assumes that the centre-of-curvature trajectories of the particle pathlines are representative of the trajectories followed by the spanwise vortices. As a proof-of-principle study, this work has been successful in accurately describing the vortex distribution very near to the ground. However, the trajectories followed by the centres-of- curvat.ure belonging to pathlines concurrently passing through the field-of-view were sporadic and uncorrelated.