Investigation on Unsteady Flow of a Turbine Stage with Negative Bowed Stator
Complicated unsteady flow in axial turbines produces high-frequency unsteady aerodynamic exciting force, which threatens the safe operation of turbines. This paper illustrates how negative-bowed stator reduces the rotor unsteady aerodynamic exciting force by unsteady flow field. With the support of three-dimensional viscous compressible Navier-Stokes equation, the single axial turbines with 0, -10 and -20 degree bowed stator are comparably investigated, aiming to identify the flow field structure difference caused by various negative-bowed degrees. The results show that negative-bowed stator strengthens the turbulence kinetic energy, which is further strengthened with the increase of negative-bowed degree. Meanwhile, the flow phenomenon including stator wakes and passage vortex is shown. In addition, the interaction of upstream negative-bowed wakes contributes to the reduction of unsteady blade load fluctuation. Furthermore, the aerodynamic exciting force decreases with the increasing negative bowed degree, while the efficiency is correspondingly reduced. This paper provides the reference for the alleviation of the harmful impact caused by unsteady interaction with the method of wake control.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1131201Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 537
 N.R. Smith, N.L. Key, “Unsteady vane boundary layer response to rotor–rotor interactions in a multistage compressor,” J. Propul. Power, vol. 30, pp. 416-425, Feb. 2014.
 S. J. Payne, R. W. Ainsworth, R. J. Miller, R. W. Mossc, and N. W. Harvey, “Unsteady loss in a high pressure turbine stage: Interaction effects,” Int. J. Heat Fluid FL., vol. 26, pp. 695-708, Oct. 2005.
 H. Zhou, Y. Mao, Q. Diao, F. Lu, and Q. Zhang, “Numerical analysis of the vibration and noise induced by the unsteady flow in a centrifugal compressor,” P. I. Mech. Eng. A-J. Pow., vol. 230, pp. 554-569, May. 2016.
 J. Bellucci, F. Rubechini, A. Arnone, L. Arcangeli, N. Maceli, B. Paradiso, et al, “Numerical and experimental investigation of axial gap variation in high-pressure steam turbine stages,” J. Eng. Gas. Turb. Power, vol. 139, p. 052603, Jan. 2017.
 G. Pullan, “Secondary flows and loss caused by blade row interaction in a turbine stage,” J. Turbomach., vol. 128, pp. 484–491, July. 2006.
 V. S. P. Chaluvadi, A. I. Kalfas, and H. P.Hodson, “Vortex transport and blade interactions in high pressure turbines,” J. Turbomach., vol.126, pp. 395–405, July. 2004.
 M. Marconcini , R. Pacciani , A. Arnone , and F. Bertini, “Low-pressure turbine cascade performance calculations with incidence variation and periodic unsteady inflow conditions,” in ASME Turbo Expo 2015, pp .V02AT38A006
 J Gao, Q Zheng, X Jia, “Performance improvement of shrouded turbines with the management of casing endwall interaction flows,” Energy, vol. 75, pp. 430-422, Oct. 2014.
 M. M.Rai, “Three-dimensional Navier-Stokes simulations of turbine rotor-stator interaction. Part I-Methodology,” J. Propul. Power, vol.5, pp. 305-311, June. 1989.
 A. A. Osipov, A. A. Rossikhin, “Calculation method for unsteady aerodynamic blade row interaction in a multistage turbomachine,” TsAGI Sci. J., vol. 45, pp.255-271, 2014.
 K. Yamada, K. Funazaki, K. Hiroma, M. Tsutsumi, Y. Hirano, and A. Matsuo,“Effect on wake passing on unsteady aerodynamic performance in a turbine stage,” in ASME Turbo Expo 2006,pp .757-767.
 P. Gaetani, G. Persico, V. Dossena, C. Osnaghi,“Investigation of the flow field in a high-pressure turbine stage for two stator-rotor axial gaps-part 2: unsteady flow field,” J. Turbomach.,vol.129, pp.572-579, July. 2007.
 U. Reinmöller, B. Stephan, S. Schmidt, and R. Niehuis. “Clocking effects in a 1.5 stage axial turbine: Steady and unsteady experimental investigations supported by numerical simulations,” in ASME Turbo Expo 2001,p. V001T03A009.
 X.F. Zhang, H.P. Hodson, N.W. Harvey, “Unsteady boundary layer studies on ultra-high-lift low-pressure turbine blades,” P. I. Mech. Eng. A-J. Pow., vol. 219, pp. 451-460, Jan. 2005.
 S. J. Gallimore，J. J. Bolger，N. A. Cumpsty, M. J. Taylor, P. I. Wright, and J. M. M. Place, “The use of sweep and dihedral in multistage axial flow compressor blading，Part I: University research and methods development,” in ASME Turbo Expo 2002,pp.33-47.
 S. J. Gallimore，J. J. Bolger，N. A. Cumpsty, M. J. Taylor, P. I. Wright, and J. M. M. Place, “The use of sweep and dihedral in multistage axial flow compressor blading, Part II: Low and high- speed designs and test verification,”in ASME Turbo Expo 2002, pp. 49-59.
 D.E. Bohn, J. Ren, C. Tümmers, M. Sell, “Unsteady 3D-numerical investigation of the influence of the blading design on the stator-rotor interaction in a 2-Stage Turbine,” in ASME Turbo Expo 2005, pp. 1285-1294.
 D.S. Weir, G.G. Podboy, “Flow measurements and multiple pure tone noise from a forward swept fan,”in 43rd AIAA Aerospace Sciences Meeting and Exhibit, p.1200.
 K. Bamberger, T. Carolus, “Optimization of axial fans with highly swept blades with respect to losses and noise reduction,”Noise Control Eng. J., vol. 60, pp. 716-725, Nov. 2012.
 H. Liu, H. Ouyang, Y. Wu, J. Tian, and Z. Du,“Investigation of unsteady flows and noise in rotor-stator interaction with adjustable lean vane,”Eng. Appl. Comp. Fluid,vol.8, pp.299-307, Nov. 2014.
 N. B. Hushmandi,Numerical Analysis of Partial Admission in Axial Turbines, KTH Industrial Engineering and Management, Stockholm,Sweden,2010, pp. 24-43.
 Y. Xie, K. Gao, J. Lan, and G. Xie,“Computational fluid dynamics modeling three-dimensional unsteady turbulent flow and excitation force in partial admission air turbine,”Math. Prob. Engr., vol. 2013, p. 251926, Nov. 2013.
 T. Matsunuma T, “Unsteady flow field of an axial-flow turbine rotor at a low Reynolds number,” J. Turbomach.,vol.129, pp.360-371, July. 2007.