Abstract
In the present paper, a laminar cavity is analysed at very low Mach numbers. The characteristics of core-vortices are proposed and commented. The experiments were performed in an open subsonic wind tunnel using particle image velocimetry (PIV). A rectangular cavity with a length-to-depth ratio of 4 was used (shallow and open type). Three different Reynolds numbers, based on cavity depth and free stream velocity, were examined (Re h =4,000, 9,000 and 13,000). The upstream boundary layer was investigated using classical hot-wire anemometry and was found to be laminar. For each Reynolds number, a total of 1,000 vectors fields were acquired. The results are given in terms of conventional quantities (mean flow velocity, turbulence characteristics, Reynolds shear stress) and also in terms of vortex characteristics (such as probability density function of vortex location, vortex size and vortex circulation). Some of these vortex characteristics are then proposed in a local averaged presentation. The extraction of vortices from instantaneous flow fields has been done through the use of a home-made algorithm based on continuous wavelet analysis.
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Özsoy, E., Rambaud, P., Stitou, A. et al. Vortex characteristics in laminar cavity flow at very low Mach number. Exp Fluids 38, 133–145 (2005). https://doi.org/10.1007/s00348-004-0845-8
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DOI: https://doi.org/10.1007/s00348-004-0845-8