International Journal of Fluid Machinery and Systems

Korean Society for Fluid machinery (한국유체기계학회)
권호 표지
DOI QR코드

DOI QR Code

Study of Stay Vanes Vortex-Induced Vibrations with different Trailing-Edge Profiles Using CFD

  • Accepted : 2009.05.27
  • Published : 2009.12.01
Download PDF
⟨ Previous Next ⟩

Abstract

The 2D flow around 13 similar stay-vane profiles with different trailing edge geometries is investigated to determinate the main characteristics of the excitation forces for each one of them and their respective dynamic behaviors when modeled as a free-oscillating system. The main goal is avoid problems with cracks of hydraulic turbines components. A stay vane profile with a history of cracks was selected as the basis for this work. The commercial finite-volume code $FLUENT^{(R)}$ was employed in the simulations of the stationary profiles and, then, modified to take into account the transversal motion of elastically mounted profiles with equivalent structural stiffness and damping. The k-$\omega$ SST turbulence model is employed in all simulations and a deforming mesh technique used for models with profile motion. The static-model simulations were carried out for each one of the 13 geometries using a constant far field flow velocity value in order to determine the lift force oscillating frequency and amplitude as a function of the geometry. The free-oscillating stay-vane simulations were run with a low mass-damping parameter ($m^*{\xi}=0.0072$) and a single mean flow velocity value (5m/s). The structural bending stiffness of the stay-vane is defined by the Reduced Velocity parameter (Vr). The dynamic analyses were divided into two sets. The first set of simulations was carried out only for one profile with $2{\leq}Vr{\leq}12$. The second set of simulations focused on determining the behavior of each one of the 13 profiles in resonance.

Keywords

References

  1. D'Agostini N., A., Saltara, F., 2007, “Simulation of vortex induced vibration of pairs of cylinders in tandem arrangement using deforming meshes,” V BBVIV, Bahia, Brazil.
  2. Fisher, F. K., Gummer, J. H.,1994, Liess, C,m “Stayvane vibrations in the Nkula Falls turbines,” Hydropower & Dams.
  3. Gummer, J. H., Hensman, P.C., August 1992, “A review of stayvane cracking in hydraulic turbines”, Water Power & Dam Construction, pp. 32-42.
  4. Gunnar, H., Olberts, D. R., “Influence of Trailing-Edge Geometry on Hydraulic-Turbine-Blade Vibration Resulting from Vortex excitation,” Journal of Basic Engineering, ASME.
  5. J. H. Gerrard, 1966, “The mechanics of the formation region of vortices behind bluff bodies,” J. Fluid Mech. 25 no. Part 2, pp. 401-413. https://doi.org/10.1017/S0022112066001721
  6. Khalak, A. Williamson C. H. K., 1999, “Motions, forces and mode transitions in vortex-induced vibrations at low massdamping,” J. Fluid and Structures 13, pp. 813-851. https://doi.org/10.1006/jfls.1999.0236
  7. Liess, C., “Flow induced stress fluctuations in stay vanes of large hydraulic turbines,” International Conference on Flow Induced Vibrations, England.
  8. Miyagawa,K., Fukao, S., Kawata, Y.,2004, “Study on stay vane instability due to Vortex shedding,” 22th IAHR Symposium on Hydraulic Machinery and Systems, Stockholm.
  9. Gissoni, H.C., 2005, “Analise mecanica de vibracoes em travessas do pre-distribuidor de turbinas hidraulicas,” Department of Mechanical Engineering, University of Sao Paulo, MsC Thesis.
  10. Meneghini, J. R., 2002, “Projetos de pesquisa no topico geracao e desprendimento de vortices no escoamento ao redor de cilindros,” Livre-Docencia, Department of Mechanical Engineering, University of Sao Paulo.
  11. Saltara,F., 1999, “Simulacao numerica do escoamento ao redor de cilindros,” Doctoral Thesis, Department of Mechanical Engineering, University of Sao Paulo.
  12. Chen, Y. N., “Behavior of Karman Vortex Streets Shed by Plates,” Research Laboratory for Vibration and Acoustics, Sulzer Brothers Limited, Switzerland.
  13. Blevins, R. D., 1990, “Flow-induced vibration,” 2nd ed., Van Nostrand Reinhold, New York.
  14. Wilcox,D.C., 1994, “Turbulence Modeling for CFD,” DCW Industries Inc., California.

Cited by

  1. An Intelligent Optimization Method for Vortex-Induced Vibration Reducing and Performance Improving in a Large Francis Turbine vol.10, pp.11, 2017, https://doi.org/10.3390/en10111901