Numerical Estimation of Torsional Dynamic Coefficients of a Hydraulic Turbine
The rotordynamic behavior of a hydraulic turbine is influenced by fluid-rotor interactions at the turbine runner. In this paper computational fluid dynamics (CFDs) are used to numerically predict the torsional dynamic coefficients due to added polar inertia, damping, and stiffness of a Kaplan turbin...
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| Format: | Article |
| Language: | English |
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Wiley
2009-01-01
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| Series: | International Journal of Rotating Machinery |
| Online Access: | http://dx.doi.org/10.1155/2009/349397 |
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| author | Martin Karlsson Håkan Nilsson Jan-Olov Aidanpää |
| author_facet | Martin Karlsson Håkan Nilsson Jan-Olov Aidanpää |
| author_sort | Martin Karlsson |
| collection | DOAJ |
| description | The rotordynamic behavior of a hydraulic turbine is influenced by fluid-rotor interactions at the
turbine runner. In this paper computational fluid dynamics (CFDs) are used to numerically predict
the torsional dynamic coefficients due to added polar inertia, damping, and stiffness of a Kaplan
turbine runner. The simulations are carried out for three operating conditions, one at about 35%
load, one at about 60% load (near best efficiency), and one at about 70% load.
The runner rotational speed is perturbed with a sinusoidal function with different frequencies in
order to estimate the coefficients of added polar inertia and damping. It is shown that the added
coefficients are dependent of the load and the oscillation frequency of the runner. This affect the
system's eigenfrequencies and damping. The eigenfrequency is reduced with up to 65% compared
to the eigenfrequency of the mechanical system without the fluid interaction. The contribution to
the damping ratio varies between 30–80% depending on the load. Hence, it is important to consider
these added coefficients while carrying out dynamic analysis of the mechanical system. |
| format | Article |
| id | doaj-art-0e014c4599734754aeece20737b640c4 |
| institution | Kabale University |
| issn | 1023-621X 1542-3034 |
| language | English |
| publishDate | 2009-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | International Journal of Rotating Machinery |
| spelling | doaj-art-0e014c4599734754aeece20737b640c42025-02-03T06:14:11ZengWileyInternational Journal of Rotating Machinery1023-621X1542-30342009-01-01200910.1155/2009/349397349397Numerical Estimation of Torsional Dynamic Coefficients of a Hydraulic TurbineMartin Karlsson0Håkan Nilsson1Jan-Olov Aidanpää2Lloyd's Register ODS, 10074 Stockholm, SwedenDepartment of Fluid Dynamics, Chalmers University of Technology, 41296 Göteborg, SwedenDivision of Solid Mechanics, Department of Mechanical Engineering, Luleå University of Technology, 97187 Luleå, SwedenThe rotordynamic behavior of a hydraulic turbine is influenced by fluid-rotor interactions at the turbine runner. In this paper computational fluid dynamics (CFDs) are used to numerically predict the torsional dynamic coefficients due to added polar inertia, damping, and stiffness of a Kaplan turbine runner. The simulations are carried out for three operating conditions, one at about 35% load, one at about 60% load (near best efficiency), and one at about 70% load. The runner rotational speed is perturbed with a sinusoidal function with different frequencies in order to estimate the coefficients of added polar inertia and damping. It is shown that the added coefficients are dependent of the load and the oscillation frequency of the runner. This affect the system's eigenfrequencies and damping. The eigenfrequency is reduced with up to 65% compared to the eigenfrequency of the mechanical system without the fluid interaction. The contribution to the damping ratio varies between 30–80% depending on the load. Hence, it is important to consider these added coefficients while carrying out dynamic analysis of the mechanical system.http://dx.doi.org/10.1155/2009/349397 |
| spellingShingle | Martin Karlsson Håkan Nilsson Jan-Olov Aidanpää Numerical Estimation of Torsional Dynamic Coefficients of a Hydraulic Turbine International Journal of Rotating Machinery |
| title | Numerical Estimation of Torsional Dynamic Coefficients of a Hydraulic Turbine |
| title_full | Numerical Estimation of Torsional Dynamic Coefficients of a Hydraulic Turbine |
| title_fullStr | Numerical Estimation of Torsional Dynamic Coefficients of a Hydraulic Turbine |
| title_full_unstemmed | Numerical Estimation of Torsional Dynamic Coefficients of a Hydraulic Turbine |
| title_short | Numerical Estimation of Torsional Dynamic Coefficients of a Hydraulic Turbine |
| title_sort | numerical estimation of torsional dynamic coefficients of a hydraulic turbine |
| url | http://dx.doi.org/10.1155/2009/349397 |
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