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Titre :
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Caractéristiques des instabilités et des processus de transition de l'écoulement situé entre un disque en rotation et sa garniture
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Titre original:
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Characteristics of instabilities and transition processes of the flow between a rotating disk and the casing
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Auteurs :
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M. Itoh ;
Y. Yamada ;
H. Nagata ;
N. Teraji
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Type de document :
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article/chapitre/communication
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Année de publication :
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1988
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Format :
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1236-1243
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Langues:
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Japonais
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Mots-clés:
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MECANIQUE DES FLUIDES
;
ECOULEMENT TURBULENT
;
VITESSE D'ECOULEMENT
;
STABILITE
;
VISCOSITE
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Résumé :
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The characteristics of instabilities and the transition processes to turbulence are studied experimentally for the flow between a rotating disk and its casing. The spectral analyses of the velocity fluctuations show that, in the case of a large clearance ratio an inviscid instability of the boundary layer flow on the rotating disk starts at the local Reynolds number of about 8 times 10 to the fourth power, which is in good agreement with that obtained theoretically in our previous work. Visualization of the flow near the rotating disk reveals that two different types of instabilities occur at any clearance ratio tested. It is believed that one of these is a viscous type and the other is an inviscid type. The characteristics of these instabilites are compared with those predicted by a linear stability analysis. The transition processes to turbulence are clarified for two different clearance ratios in view of the velocity power spectrum.
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Source :
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Nippon kikai gokkai rombushu, vol.54, n°502
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