Natural frequencies and modes shapes of two rigid bladed discs on the shaft

• Autorzy: Rządkowski R. , Sokołowski J.
• Języki publikacji: EN

Abstrakty

EN

The dynamic behavior of a rotor consisting of two bladed discs on a solid shaft is considered. The effect of shaft flexibility on the dynamic characteristics of the bladed discs and the coupling effects between the shaft and bladed disc modes are investigated. Results presented for various cases with differing blade flexibility show clearly the coupling effects in a bladed disc-shaft system. Interference diagrams are developed, from which the dynamic behavior of a system can be predicted for differing flexibility relationships between the solid shafts and the bladed discs. In this study, the global rotating mode shapes of flexible bladed disc-shaft assemblies have been calculated. Rotational effects such as centrifugal stiffening have been accounted for, and all the possible couplings between the flexible parts have been allowed. Gyroscopic effects have been included in the shaft with two discs. Calculated natural frequencies obtained from the blade, shaft, bladed disc and shaft with two discs have been checked to determine resonance conditions and coupling effects. The calculations have shown the influence of the shaft on the natural frequencies of the bladed discs up to one nodal diameter frequencies. The torsional frequency of the shaft with two discs is coupled with the zero nodal diameter modes of the single bladed discs. The bending modes of the shaft are coupled with one nodal diameter modes of the bladed discs. It is shown that including the shaft in the bladed discs model is important from a designer's point of view and can change the spectrum of frequencies considerably.

Słowa kluczowe

EN

natural frequencies; bladed disc-shaft

• Wydawca: Politechnika Gdańska
• Czasopismo: TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk
• Rocznik: 2004
• Tom: Vol. 8, No 1
• Strony: 51--69
• Opis fizyczny: Bibliogr. 12 poz., rys.

Twórcy

autor

Rządkowski R.

autor

Sokołowski J.

• Department of Dynamics of Machines, Institute of Fluid Machinery, Polish Academy of Sciences, J. Fiszera 14, 80-952 Gdańsk, Poland,

Bibliografia

• [1] Berger H and Kulig T S 1981 Simulation Models for Calculating the Torsional Vibrations of Large Turbine-generator Units after Electrical System Faults, Simens Forsch. u. Entwickl. – Ber., Springer-Verlag, 10 (4) 237
• [2] Rao J S 1991 Rotor Dynamics, 2nd Edition, John Wiley & Sons
• [3] Chivens D R and Nelson H D 1975 J. Engng. for Industry 97 881
• [4] Rzadkowski R 1998 Dynamics of Rotor Steam Turbine Rotor Blading: Part Two – Bladed Discs, Fluid Flow Machinery, Wroclaw, Ossolineum 22
• [5] Dubigeon S and Michon J C 1986 J. Sound and Vibration 106 (1) 53
• [6] Huang S C and Ho K B 1996 Trans. ASME 118 100
• [7] Jacquet-Richardet G, Ferraris G and Rieutord P 1996 J. Sound and Vibration 191 (5) 901
• [8] Kanki H and Yammamoto Y 1989 Proc. 12 th Biennial ASME Conf. Mechanical Vibration and Noise, Montreal, Canada, Rotating Machinery Dynamics DE 18 (1) 17
• [9] Khader N and Masoud S 1991 J. Sound and Vibration 149 (3) 471
• [10] Okabe A, Kaneeko R, Matsushita O, Namura K and Yoshida T 1989 Proc. 12 th Biennial ASME Conf. Mechanical Vibration and Noise, Montreal, Canada, Rotating Machinery Dynamics, DE 18 (1) 135
• [11] Lalane M and Ferraris G 1990 Rotordynamics Prediction in Engineering, John Wiley & Sons
• [12] Bolcs A and Fransson T H 1986 Communication du LTAT–EPFL 13 174