Experimental Study of a Low-Specific Speed Francis Model Runner during Resonance
An analysis of the pressure in a runner channel of a low-specific speed Francis model runner during resonance is presented, which includes experiments and the development of a pressure model to estimate both the convective and acoustic pressure field from the measurements. The pressure was measured...
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| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2018-01-01
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| Series: | Shock and Vibration |
| Online Access: | http://dx.doi.org/10.1155/2018/5796875 |
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| _version_ | 1832567687222394880 |
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| author | Einar Agnalt Petter Østby Bjørn W. Solemslie Ole G. Dahlhaug |
| author_facet | Einar Agnalt Petter Østby Bjørn W. Solemslie Ole G. Dahlhaug |
| author_sort | Einar Agnalt |
| collection | DOAJ |
| description | An analysis of the pressure in a runner channel of a low-specific speed Francis model runner during resonance is presented, which includes experiments and the development of a pressure model to estimate both the convective and acoustic pressure field from the measurements. The pressure was measured with four pressure sensors mounted in the runner hub along one runner channel. The mechanical excitation of the runner corresponded to the forced excitation from rotor-stator interaction. The rotational speed was used to control the excitation frequency. The measurements found a clear resonance peak in the pressure field excited by the second harmonic of the guide vane passing frequency. From the developed pressure model, the eigenfrequency and damping were estimated. The convective pressure field seems to diminish almost linearly from the inlet to outlet of the runner, while the acoustic pressure field had the highest amplitudes in the middle of the runner channel. At resonance, the acoustic pressure clearly dominated over the convective pressure. As the turbine geometry is available to the public, it provides an opportunity for the researchers to verify their codes at resonance conditions. |
| format | Article |
| id | doaj-art-d0e1945bf0bd40eea9fa969d6fed8e2b |
| institution | Kabale University |
| issn | 1070-9622 1875-9203 |
| language | English |
| publishDate | 2018-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Shock and Vibration |
| spelling | doaj-art-d0e1945bf0bd40eea9fa969d6fed8e2b2025-02-03T01:00:54ZengWileyShock and Vibration1070-96221875-92032018-01-01201810.1155/2018/57968755796875Experimental Study of a Low-Specific Speed Francis Model Runner during ResonanceEinar Agnalt0Petter Østby1Bjørn W. Solemslie2Ole G. Dahlhaug3Waterpower Laboratory, Department of Energy and Process Engineering, NTNU—Norwegian University of Science and Technology, Trondheim, NorwayWaterpower Laboratory, Department of Energy and Process Engineering, NTNU—Norwegian University of Science and Technology, Trondheim, NorwayWaterpower Laboratory, Department of Energy and Process Engineering, NTNU—Norwegian University of Science and Technology, Trondheim, NorwayWaterpower Laboratory, Department of Energy and Process Engineering, NTNU—Norwegian University of Science and Technology, Trondheim, NorwayAn analysis of the pressure in a runner channel of a low-specific speed Francis model runner during resonance is presented, which includes experiments and the development of a pressure model to estimate both the convective and acoustic pressure field from the measurements. The pressure was measured with four pressure sensors mounted in the runner hub along one runner channel. The mechanical excitation of the runner corresponded to the forced excitation from rotor-stator interaction. The rotational speed was used to control the excitation frequency. The measurements found a clear resonance peak in the pressure field excited by the second harmonic of the guide vane passing frequency. From the developed pressure model, the eigenfrequency and damping were estimated. The convective pressure field seems to diminish almost linearly from the inlet to outlet of the runner, while the acoustic pressure field had the highest amplitudes in the middle of the runner channel. At resonance, the acoustic pressure clearly dominated over the convective pressure. As the turbine geometry is available to the public, it provides an opportunity for the researchers to verify their codes at resonance conditions.http://dx.doi.org/10.1155/2018/5796875 |
| spellingShingle | Einar Agnalt Petter Østby Bjørn W. Solemslie Ole G. Dahlhaug Experimental Study of a Low-Specific Speed Francis Model Runner during Resonance Shock and Vibration |
| title | Experimental Study of a Low-Specific Speed Francis Model Runner during Resonance |
| title_full | Experimental Study of a Low-Specific Speed Francis Model Runner during Resonance |
| title_fullStr | Experimental Study of a Low-Specific Speed Francis Model Runner during Resonance |
| title_full_unstemmed | Experimental Study of a Low-Specific Speed Francis Model Runner during Resonance |
| title_short | Experimental Study of a Low-Specific Speed Francis Model Runner during Resonance |
| title_sort | experimental study of a low specific speed francis model runner during resonance |
| url | http://dx.doi.org/10.1155/2018/5796875 |
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