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Fish injury and mortality during passage through pumping stations / B. P. M. van Esch in Transactions of the ASME . Journal of fluids engineering, Vol. 134 N° 7 (Juillet 2012) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 134 N° 7 (Juillet 2012) . - 09 p. Titre : Fish injury and mortality during passage through pumping stations Type de document : texte imprimé Auteurs : B. P. M. van Esch, Auteur Année de publication : 2012 Article en page(s) : 09 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : fish;  centrifugal  pumps;  computational  fluid  dynamics  (CFD) Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : An unwanted side effect of pumping stations is that fish suffer from injury and mortality when passing through the pumps and that fish migration is hampered. In recent years, the development of so-called fish-friendly pumping stations has received increasing attention from European governmental institutions and pump manufacturers. In the Netherlands, many field studies have been conducted over the last decade to assess the chances of survival for fish passing through pumps. A clear correlation between observed injury or mortality and, for example, flow rate, shaft speed, or pump type could not be established. This paper presents a new analysis of these field studies. It uses American studies on the biological criteria for fish injury, the most important of which are pressure changes, shear forces, and mechanical injury. A blade strike model is adapted to fish passing through centrifugal pumps of radial, mixed-flow, and axial type. It reveals the relation between fish injury and the type of pump, its size, shaft speed, and pressure head. The results correlate fairly well with experiments. The flow through a typical mixed-flow pump is calculated using computational fluid dynamics (CFD). The results show that pressure fluctuations and shear forces are not likely to add much to fish mortality. Guidelines for the design and selection of fish-friendly pumps are given with the introduction of two new dimensionless numbers: the blade strike probability factor and the blade strike velocity factor. It shows that fish-friendliness of pumps decreases with increasing specific speed value. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA4000134000007 [...] [article] Fish injury and mortality during passage through pumping stations [texte imprimé] / B. P. M. van Esch, Auteur . - 2012 . - 09 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 134 N° 7 (Juillet 2012) . - 09 p. Mots-clés : fish;  centrifugal  pumps;  computational  fluid  dynamics  (CFD) Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : An unwanted side effect of pumping stations is that fish suffer from injury and mortality when passing through the pumps and that fish migration is hampered. In recent years, the development of so-called fish-friendly pumping stations has received increasing attention from European governmental institutions and pump manufacturers. In the Netherlands, many field studies have been conducted over the last decade to assess the chances of survival for fish passing through pumps. A clear correlation between observed injury or mortality and, for example, flow rate, shaft speed, or pump type could not be established. This paper presents a new analysis of these field studies. It uses American studies on the biological criteria for fish injury, the most important of which are pressure changes, shear forces, and mechanical injury. A blade strike model is adapted to fish passing through centrifugal pumps of radial, mixed-flow, and axial type. It reveals the relation between fish injury and the type of pump, its size, shaft speed, and pressure head. The results correlate fairly well with experiments. The flow through a typical mixed-flow pump is calculated using computational fluid dynamics (CFD). The results show that pressure fluctuations and shear forces are not likely to add much to fish mortality. Guidelines for the design and selection of fish-friendly pumps are given with the introduction of two new dimensionless numbers: the blade strike probability factor and the blade strike velocity factor. It shows that fish-friendliness of pumps decreases with increasing specific speed value. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA4000134000007 [...]

Performance and radial loading of a mixed-flow pump under non-uniform suction flow / B. P. M. van Esch in Transactions of the ASME . Journal of fluids engineering, Vol. 131 N° 5 (Mai 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 131 N° 5 (Mai 2009) . - 7 p. Titre : Performance and radial loading of a mixed-flow pump under non-uniform suction flow Type de document : texte imprimé Auteurs : B. P. M. van Esch, Auteur Année de publication : 2009 Article en page(s) : 7 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : nonuniform  suction  velocity  profile;  mixed-flow  pump;  hydrodynamic  forces Résumé : Many centrifugal pumps have a suction velocity profile, which is nonuniform, either by design like in double-suction pumps, sump pumps, and in-line pumps, or as a result of an installation close to an upstream disturbance like a pipe bend. This paper presents an experimental study on the effect of a nonuniform suction velocity profile on performance of a mixed-flow pump and hydrodynamic forces on the impeller. In the experiments, a newly designed dynamometer is used, equipped with six full Wheatstone bridges of strain gauges to measure the six generalized force components. It is placed in between the shaft of the pump and the impeller and corotates with the rotor system. A high accuracy is obtained due to the orthogonality of bridge positioning and the signal conditioning electronics embedded within the dynamometer. The suction flow distribution to the pump is adapted using a pipe bundle situated in the suction pipe. Results of measurements show the influence of the suction flow profile and blade interaction on pump performance and forces. Among the most important observations are a backward whirling motion of the rotor system and a considerable steady radial force. En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] Performance and radial loading of a mixed-flow pump under non-uniform suction flow [texte imprimé] / B. P. M. van Esch, Auteur . - 2009 . - 7 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 131 N° 5 (Mai 2009) . - 7 p. Mots-clés : nonuniform  suction  velocity  profile;  mixed-flow  pump;  hydrodynamic  forces Résumé : Many centrifugal pumps have a suction velocity profile, which is nonuniform, either by design like in double-suction pumps, sump pumps, and in-line pumps, or as a result of an installation close to an upstream disturbance like a pipe bend. This paper presents an experimental study on the effect of a nonuniform suction velocity profile on performance of a mixed-flow pump and hydrodynamic forces on the impeller. In the experiments, a newly designed dynamometer is used, equipped with six full Wheatstone bridges of strain gauges to measure the six generalized force components. It is placed in between the shaft of the pump and the impeller and corotates with the rotor system. A high accuracy is obtained due to the orthogonality of bridge positioning and the signal conditioning electronics embedded within the dynamometer. The suction flow distribution to the pump is adapted using a pipe bundle situated in the suction pipe. Results of measurements show the influence of the suction flow profile and blade interaction on pump performance and forces. Among the most important observations are a backward whirling motion of the rotor system and a considerable steady radial force. En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]