A reduced order numerical method for subsonic stall flutter analysis of steam turbine blade cascade

0541860 - ÚT 2022 RIV PL eng C - Konferenční příspěvek (zahraniční konf.)
Prasad, Chandra Shekhar - Šnábl, Pavel - Pešek, Luděk
A reduced order numerical method for subsonic stall flutter analysis of steam turbine blade cascade.
14th International Conference on Dynamics of Rotating Machines : SIRM 2021. Gdaňsk: IMP PAN, 2021 - (Žywica, G.; Szolc, T.), s. 381-390. ISBN 978-83-88237-98-0.
[SIRM 2021 International Conference on Dynamics of Rotating Machines /14./. Gdaňsk (PL), 17.02.2021-19.02.2021]
Grant CEP: GA ČR(CZ) GA20-26779S
Institucionální podpora: RVO:61388998
Klíčová slova: reduced order * method subsonic stall flutter * blade cascade
Obor OECD: Applied mechanics

In this paper aeroelastic stability analysis of power turbine for subsonic stall flutter is presented. A medium fidelity reduced order numerical model based on hybrid boundary element method is developed to model the flow in 3D blade cascade. The reduced order flow solver is developed on the basis of viscous-inviscid weak coupling approach. In this approach panel method is used for inviscid part and boundary layer method for the viscous part whereas, discrete vortex particle method is employed for the unsteady wake modeling. The hybrid flow solver is used to model separated flow and stall flutter in the 3D blade cascade at subsonic flow speed. The subsonic stall flutter in turbomachinery can be quantified by aerodynamic damping coefficient w.r.t. inter blade phase angle in traveling wave mode. Therefore, aerodynamic damping coefficient at different inter blade phase angle is estimated using modified panel method flow model for 3D linear blade cascade for subsonic stall flutter in torsional mode oscillation. The estimated results are validated against experimental measurements as well Navier-Stokes equation based high fidelity computational fluid dynamics model. The simulated results show good agreement with experimental data. The reduced order flow solver also shows significant reduction in computational time compared to Navier Stoke based CFD models. Therefore, successful implementation of the proposed boundary element based flow model for subsonic stall flutter in cascade will have significant impact on the computational time reduction which can facilitate to iterate different blade profile in very short time period at preliminary LP turbine design stage, thus, make the blade design optimization and to analysis of aeroelastic stability parameters in steam turbine application faster.
Trvalý link: http://hdl.handle.net/11104/0320692