Investigation of a wake decay behind a circular disk in a hydro channel at high Reynolds numbers
I.V. Naumov1, I.V. Litvinov1, R.F. Mikkelsen2, and V.L. Okulov1,2
1 Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
2 Danish Technical University, Lyngby, Denmark
E-mail: naumov@itp.nsc.ru
Keywords: wake flow past a body, free-stream flow turbulence level, velocity deficit, similarity of velocity profiles, laser Doppler anemometry, PIV
Pages: 657–665
Abstract
LDA and PIV techniques were used to study the decay of an axisymmetrical turbulent wake originated downstream an immobile disk in a water flume for Reynolds numbers Re = 1.5-2.4×105. Data were compared with experiments performed with a set of thermo-anemometers behind a disk in a wind tunnel at lower Reynolds numbers (Re = 1.3-2.6×104).
Observations for a new range of Reynolds number confirmed that the velocity distribution in the disk wake keeps self-similarity. The decay of a wake by the power law -2/3 in the presented experiments remains until the maximum deficit of velocity becomes comparable with the turbulent pulsation level in the free-stream (less than 2 %).
DOI: 10.1134/S0869864315060013
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