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Vibration diagnosis featuring blade-shaft coupling effect of turbine rotor models / Norihisa Anegawa in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 2 (Fevrier 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 2 (Fevrier 2011) . - 08 p. Titre : Vibration diagnosis featuring blade-shaft coupling effect of turbine rotor models Type de document : texte imprimé Auteurs : Norihisa Anegawa, Auteur ; Hiroyuki Fujiwara, Auteur ; Osami Matsushita, Auteur Année de publication : 2012 Article en page(s) : 08 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Blades  Couplings  Nuclear  power  stations  Rotors  Shafts  Steam  turbines  Turbines  Vibrations Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : As is well known, zero and one nodal diameter (k=0 and k=1) modes of a blade system interact with the shaft system. The former couples with torsional and/or axial shaft vibrations, and the latter with bending shaft vibrations. This paper addresses the latter. With respect to k=1 modes, we discuss, from experimental and theoretical viewpoints, in-plane blades and out-of-plane blades attached radially to a rotating shaft. We found that when we excited the shaft at the rotational speed of Omega=|omegab−omegas| (where omegab is the blade natural frequency, omegas the shaft natural frequency, and Omega is the rotational speed), the exciting frequency nu=omegas induced shaft-blade coupling resonance. In addition, in the case of the in-plane blade system, we encountered an additional resonance attributed to deformation caused by gravity. In the case of the out-of-plane blade system, we experienced two types of abnormal vibrations. One is the additional resonance generated at Omega=omegab/2 due to the unbalanced shaft and the anisotropy of bearing stiffness. The other is a flow-induced, self-excited vibration caused by galloping due to the cross-sectional shape of the blade tip because this instability disappeared in the rotation test inside a vacuum chamber. The two types of abnormal vibrations occurred at the same time, and both led to the entrainment phenomenon, as identified by our own frequency analysis technique. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Vibration diagnosis featuring blade-shaft coupling effect of turbine rotor models [texte imprimé] / Norihisa Anegawa, Auteur ; Hiroyuki Fujiwara, Auteur ; Osami Matsushita, Auteur . - 2012 . - 08 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 2 (Fevrier 2011) . - 08 p. Mots-clés : Blades  Couplings  Nuclear  power  stations  Rotors  Shafts  Steam  turbines  Turbines  Vibrations Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : As is well known, zero and one nodal diameter (k=0 and k=1) modes of a blade system interact with the shaft system. The former couples with torsional and/or axial shaft vibrations, and the latter with bending shaft vibrations. This paper addresses the latter. With respect to k=1 modes, we discuss, from experimental and theoretical viewpoints, in-plane blades and out-of-plane blades attached radially to a rotating shaft. We found that when we excited the shaft at the rotational speed of Omega=|omegab−omegas| (where omegab is the blade natural frequency, omegas the shaft natural frequency, and Omega is the rotational speed), the exciting frequency nu=omegas induced shaft-blade coupling resonance. In addition, in the case of the in-plane blade system, we encountered an additional resonance attributed to deformation caused by gravity. In the case of the out-of-plane blade system, we experienced two types of abnormal vibrations. One is the additional resonance generated at Omega=omegab/2 due to the unbalanced shaft and the anisotropy of bearing stiffness. The other is a flow-induced, self-excited vibration caused by galloping due to the cross-sectional shape of the blade tip because this instability disappeared in the rotation test inside a vacuum chamber. The two types of abnormal vibrations occurred at the same time, and both led to the entrainment phenomenon, as identified by our own frequency analysis technique. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]