Supression of classical flutter ocsillations in bladed wheel using inner damping effect

0535110 - ÚT 2021 RIV GR eng C - Konferenční příspěvek (zahraniční konf.)
Pešek, Luděk - Šnábl, Pavel - Prasad, Chandra Shekhar
Supression of classical flutter ocsillations in bladed wheel using inner damping effect.
EURODYN 2020. Vol. 1. Athens: National Technical University of Athens (NTUA), 2020 - (Papadrakakis, M.; Fragiadakis, M.; Papadimitriou, C.), s. 402-411. ISBN 978-618-85072-0-3.
[EURODYN 2020 /11./. Athény (GR), 23.11.2020-26.11.2020]
Grant CEP: GA ČR(CZ) GC19-02288J
Institucionální podpora: RVO:61388998
Klíčová slova: blade * flutter * travelling wave * van der pol model
Obor OECD: Applied mechanics
https://www.easdprocedia.org/conferences/easd-conferences/eurodyn-2020/9031

Inner material damping effect for reduction of self-excited vibrations due to aeroelastic instability is studied on a numerical reduced model of a rotating turbine wheel with 66 blades. The aerodynamic nozzle excitation of the rotating wheel arises from the spatially periodical flow of steam through the stator blade cascade. This excitation causes travelling deformation waves in the wheel. The analysis of forced vibration of the wheel under selfexcitation is oriented on the narrow frequency range and therefore the bladed wheel is modelled by a modal synthesis method. The self-excited aero-elastic forces are described by Van der Pol model acting herein independently to the 1th axial flexural mode of each blade of the wheel. Numerical simulations showed a very fast entry of amplitudes increase due to selfexcitation.
The initial forced vibration mode by nozzle excitation was decisive for the vibration pattern of self-excitation. Its suppression depended on the ratio between the intensity factor of self-excitation and the size of proportional damping describing the inner damping.
Trvalý link: http://hdl.handle.net/11104/0315410