International Journal of Fluid Machinery and Systems

한국유체기계학회 (Korean Society for Fluid machinery)
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Characteristics of Synchronous and Asynchronous modes of fluctuations in Francis turbine draft tube during load variation

  • Goyal, Rahul (Department of Mechanical and Industrial Engineering, Indian Institute of Technology) ;
  • Cervantes, Michel J. (Division of Fluid and Experimental Mechanics, Department of Engineering Sciences and Mathematics, Lulea University of Technology) ;
  • Gandhi, Bhupendra K. (Department of Mechanical and Industrial Engineering, Indian Institute of Technology)
  • 투고 : 2017.02.01
  • 심사 : 2017.05.16
  • 발행 : 2017.06.30
⟨ 이전 논문 다음 논문 ⟩

초록

Francis turbines are often operated over a wide load range due to high flexibility in electricity demand and penetration of other renewable energies. This has raised significant concerns about the existing designing criteria. Hydraulic turbines are not designed to withstand large dynamic pressure loadings on the stationary and rotating parts during such conditions. Previous investigations on transient operating conditions of turbine were mainly focused on the pressure fluctuations due to the rotor-stator interaction. This study characterizes the synchronous and asynchronous pressure and velocity fluctuations due to rotor-stator interaction and rotating vortex rope during load variation, i.e. best efficiency point to part load and vice versa. The measurements were performed on the Francis-99 test case. The repeatability of the measurements was estimated by providing similar movement to guide vanes twenty times for both load rejection and load acceptance operations. Synchronized two dimensional particle image velocimetry and pressure measurements were performed to investigate the dominant frequencies of fluctuations, vortex rope formation, and modes (rotating and plunging) of the rotating vortex rope. The time of appearance and disappearance of rotating and plunging modes of vortex rope was investigated simultaneously in the pressure and velocity data. The asynchronous mode was observed to dominate over the synchronous mode in both velocity and pressure measurements.

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과제정보

연구 과제 주관 기관 : Swedish Water Power Center (SVC), Norwegian Hydropower Centre (NVKS)

참고문헌

  1. Trivedi C., Gandhi B. K., and Cervantes M. J., 2013, "Effect of Transients on Francis Turbine Runner Life: A Review," Journal of Hydraulic Research, Vol. 51, No. 2, pp. 121-132. https://doi.org/10.1080/00221686.2012.732971
  2. Trivedi C., 2014, "Investigation of transient pressure loading on a high head model Francis turbine," Ph. D. Thesis, Department of Engineering Science and Mathematics, Lulea University of Technology, Lulea, Sweden.
  3. Trivedi, C., Cervantes, M. J., Gandhi, B. K., and Dahlhaug, O. G., 2014, "Pressure Measurements on a High Head Francis Turbine during Load Acceptance and Rejection," Journal of Hydraulic Research, Vol. 52, No. 2, pp. 283-297. https://doi.org/10.1080/00221686.2013.854846
  4. Amiri, K., Mulu, B., Raisee, M., and Cervantes, M. J., 2015, "Unsteady Pressure Measurements on the Runner of a Kaplan Turbine during Load Acceptance and load Rejection," Journal of Hydraulic Research, Vol. 54, No. 1, pp. 56-73.
  5. Amiri, K., Mulu, B., Cervantes, M. J., and Raisee, M., 2016, "Effect of load variation on a Kaplan turbine," IJFMS, Vol. 9, No. 2, pp. 182-193. https://doi.org/10.5293/IJFMS.2016.9.2.182
  6. Goyal, R., Trivedi, C., Gandhi, B., K., Cervantes, M., J., and Dahlhaug, O., G., 2016, "Transient pressure measurements at part load operating condition of a high head model Francis turbine" Sadhana, Vol. 41, No. 11, pp. 1311-1320.
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  8. Alligne, S., Nicolet, C., Allenbach, P., Kawkabani, B., Simond, J.-J., Avellan, F., 2009, "Influence of the Francis Turbine location under vortex rope excitation on the Hydraulic System Stability," IJFMS, Vol. 2, No. 4, pp. 286-294. https://doi.org/10.5293/IJFMS.2009.2.4.286
  9. Nishi, M., Matsunaga, S., Kubota, T., and Senoo, Y., 1982, "Study on swirl flow and surge in an elbow type draft tube," In: Proceedings of the 10th IAHR symposium, Tokyo, Japan, Vol. 1, pp. 557-568.
  10. Trivedi, C., Cervantes, and Dahlhaug, O. G., 2014, "Experimental and Numerical Studies of a High-Head Francis Turbine: A Review of the Francis-99 Test Case," Energies, Vol. 9, No. 2, pp. 74.
  11. IEC 60041, 1991-1, "Field acceptance tests to determine the hydraulic performance of hydraulic turbines, storage pumps, and pump-turbines," International Electrotechnical Commission, Third Edition.
  12. IEC 60193, 1999-11, "Hydraulic turbines, storage pumps and pump-turbines - Model acceptance tests," International Electrotechnical Commission.
  13. ASME PTC 18, 2011, "Hydraulic Turbines and Pump-Turbines, Performance Test Codes", Three Park Avenue, New York, NY 10016 USA.
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피인용 문헌

  1. Investigation of the unsteady pressure pulsations in the prototype Francis turbines during load variation and startup vol.9, pp.6, 2017, https://doi.org/10.1063/1.4994884