Aeroelastic Behaviour of Turbine Blade Row in 3D Viscous Flow

Authors

V. I. Gnesin, A. Podgorny Institute of Mechanical Engineering Problems of NASU (2/10, Pozharsky str., Kharkiv, 61046, Ukraine), e-mail: gnesin@ukr.net, ORCID: 0000-0001-6411-6158
L. V. Kolodiazhnaya, A. Podgorny Institute of Mechanical Engineering Problems of NASU (2/10, Pozharsky str., Kharkiv, 61046, Ukraine), ORCID: 0000-0001-5469-4325
R. Rzadkowski, The Szewalski Institute of Fluid-Flow Machinery Polish Academy of Sciences (14, Fiszera St., Gdańsk 80-231, Poland), e-mail:  z3@imp.gda.pl

Abstract

This paper presents the results of a numerical analysis of the aeroelastic behaviour of the oscillating blade row of a turbine stage in the 3D flow of viscous gas, taking into account the non-uniform pressure distribution in the circumferential direction behind the blade rotor. The numerical method is based upon the solution of the coupled problem of the unsteady aerodynamics and blade elastic oscillations in the unsteady spatial gas flow through the blade row of the axial turbine last stage. 3D viscous gas flow through the turbine stage with  periodicity on the whole annulus is described by  the unsteady Navier-Stokes equations in the form of conservation laws, which are integrated using the explicit monotonous finite-volume Godunov-Kolgan  difference scheme and a  moving hybrid H-O grid. The dynamic analysis uses a modal approach and 3D finite element model of a blade. The investigations showed that the unsteady pressure distribution in the circumferential direction affects the unsteady loads and modes of blade oscillations. The presented method for solving the coupled aero-elastic problem makes it possible to predict the amplitude-frequency spectrum of blade oscillations in gas flow including the forced oscillations and self-excited oscillations (flutter or auto-oscillations).

Keywords: aeroelastic behaviour; viscous flow; blade row; auto-oscillations; coupled problem; unsteady load

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References

1. Gnesin, V., Rzadkowski, R., & Kolodyazhnaya, L. (2001, September). Coupled Fluid-Structure Problem for 3D Transonic Flow Through a Turbine Stage with Oscillating Blades. Rroc. Of 5th Intern. Symp. On Exper. and Comput. Aerothermodynamic of Internal Flows, (pp. 275–284), Gdansk, Poland.
2. Baldwin, B. & Lomax, H. (1978). Thin layer approximation and algebraic model for separated turbulent flow. AIAA Paper 78–0257, pp. 1−45. https://doi.org/10.2514/6.1978-257
3. Gnesin, V., Rzadkowski, R., & Kolodyazhnaya, L. (2010). Numerical Modelling of fluid–structure interaction in a turbine stage for 3D viscous flow in nominal and off−design regimes. Proc. of ASME, TURBO-EXPO 2010, GT2010−23779, Glasgow, UK, pp. 1−9. https://doi.org/10.1115/GT2010-23779
4. Gnesin, V. I. & Kolodyazhnaya, L. V. (1999). Numerical Modelling of Aeroelastic Behaviour for Oscillating Turbine Blade Row in 3D Transonic Ideal Flow. J. of Mech. Eng., vol. 1, no. 2, pp. 65–76.
5. Gnesin, V. I., Kolodyazhnaya, L. V., & Rzadkowski, R. (2004). A numerical modeling of stator-rotor interaction in a turbine stage with oscillating blades. J. of Fluid and Structure, no. 19, pp. 1141–1153. https://doi.org/10.1016/j.jfluidstructs.2004.07.001
6. Rzadkowski, R., Gnesin, V. I., & Kolodyazhnaya, L. V. (2015, September). Rotor Blade Flutter in Last Stage of LP Steam Turbine. Proc. of the 14th Intern. Symposium on Unsteady Aerodynamics, Aeroacoustics & Aeroelasticity of Turbomachines ISUAAAT14 I14-S1-4, (pp. 1–6), Stockholm, Sweden.
7. Gnesin, V. I. & Kolodyazhnaya, L. V. (2009). Aeroelastic Phenomena in Turbomachines. Aerodynamics and Aeroacoustics: Problems and Perspectives, no. 3, pp. 53–62 (in Russian).

Received 24 January 2018

Published 30 March 2018