High speed visualizations of the cavitating vortices of 2D mixing layer
Langue
en
Article de revue
Ce document a été publié dans
European Journal of Mechanics - B/Fluids. 2012, vol. 31, p. 171-180
Elsevier
Résumé en anglais
The present study investigates experimentally vortex dynamics of a cavitating two-dimensional mixing layer at a high Reynolds number in order to determine the effect of growth and collapse of cavitation. The dynamics and ...Lire la suite >
The present study investigates experimentally vortex dynamics of a cavitating two-dimensional mixing layer at a high Reynolds number in order to determine the effect of growth and collapse of cavitation. The dynamics and the topology of the vorticity regions corresponding to the low pressure area where cavitation effects take place are studied from the single phase state to highly cavitating conditions. LDV techniques are used in order to characterize the pattern of the turbulent single phase flow. High-speed visualizations have been performed using a specific image processing of time series to highlight the behaviour and dynamics of the vapour phase. Visualizations, image processing and statistical analysis enable the estimation of the convective velocity and the shedding frequency of the cavitating Kelvin-Helmholtz vortices. The measured visual vapour thickness grows linearly as the Kelvin-Helmholtz instability develops and its expansion rate stays constant for the range of cavitation levels studied. The vortex pairing phenomenon is also analysed. Results show that the spatial development of the mixing area is slightly affected by the vapour phase allowing a self-similar behaviour of the mean motion.< Réduire
Mots clés en anglais
Vortex dynamics
Cavitation
Image analysis
Turbulent mixing layer
Origine
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