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Unsteady cavitation at the tongue of the volute of a centrifugal pump / Rudolf Bachert in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 6 (Juin 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 6 (Juin 2010) . - 06 p. Titre : Unsteady cavitation at the tongue of the volute of a centrifugal pump Type de document : texte imprimé Auteurs : Rudolf Bachert, Auteur ; Bernd Stoffel, Auteur ; Matevž Dular, Auteur Année de publication : 2010 Article en page(s) : 06 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : flow  (dynamics);  impellers;  cavitation;  pumps;  blades;  centrifugal  pumps Résumé : The paper deals with unsteady effects of cavitation at the tongue of the volute of a centrifugal pump. For the investigations parts of the volute casing, including the tongue and the hub of the impeller, were made of acrylic glass. Experiments were carried out at a flow rate above optimal value (slight overload) and at 3% head drop conditions. In this operating point there was no cavitation present in the impeller of the pump, hence, the whole 3% head drop resulted from cavitation on the tongue of the volute. By use of particle image velocimetry combined with special fluorescent particles it was possible to obtain information about the velocity field outside and inside the cavitating zone. An additional camera provided information about the location and extent of cavitation. The results imply that cloud cavitation similar to the one seen on single hydrofoils appears on the tongue. Periodical evolution of cavitation structures, from incipient to developed, with cavitation cloud shedding, is seen during each passing of a blade. The Results imply that greater consideration should be given to the possibility of cavitation appearance on the tongue of the volute as it is possible that this cavitation location alone causes the 3% head drop. Moreover, the appearance of unsteady cavitation in a higher-pressure region, such as the volute of the pump, can cause severe erosion to the solid surfaces. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] Unsteady cavitation at the tongue of the volute of a centrifugal pump [texte imprimé] / Rudolf Bachert, Auteur ; Bernd Stoffel, Auteur ; Matevž Dular, Auteur . - 2010 . - 06 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 6 (Juin 2010) . - 06 p. Mots-clés : flow  (dynamics);  impellers;  cavitation;  pumps;  blades;  centrifugal  pumps Résumé : The paper deals with unsteady effects of cavitation at the tongue of the volute of a centrifugal pump. For the investigations parts of the volute casing, including the tongue and the hub of the impeller, were made of acrylic glass. Experiments were carried out at a flow rate above optimal value (slight overload) and at 3% head drop conditions. In this operating point there was no cavitation present in the impeller of the pump, hence, the whole 3% head drop resulted from cavitation on the tongue of the volute. By use of particle image velocimetry combined with special fluorescent particles it was possible to obtain information about the velocity field outside and inside the cavitating zone. An additional camera provided information about the location and extent of cavitation. The results imply that cloud cavitation similar to the one seen on single hydrofoils appears on the tongue. Periodical evolution of cavitation structures, from incipient to developed, with cavitation cloud shedding, is seen during each passing of a blade. The Results imply that greater consideration should be given to the possibility of cavitation appearance on the tongue of the volute as it is possible that this cavitation location alone causes the 3% head drop. Moreover, the appearance of unsteady cavitation in a higher-pressure region, such as the volute of the pump, can cause severe erosion to the solid surfaces. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]