Study of dry-friction damping effect on two simplified models of flutter oscillations

0507377 - ÚT 2020 RIV PL eng C - Konferenční příspěvek (zahraniční konf.)
Pešek, Luděk - Půst, Ladislav - Šnábl, Pavel
Study of dry-friction damping effect on two simplified models of flutter oscillations.
Advances in Mechanism and Machine Science. Krakow: Springer Nature Switzerland, 2019 - (Uhl, T.), s. 3419-3428, č. článku 00730337. 73. ISBN 978-3-030-20130-2. ISSN 2211-0984. E-ISSN 2211-0992.
[IFTOMM /15./. Krakow (PL), 30.06.2019-04.07.2019]
Grant CEP: GA ČR(CZ) GC19-02288J
Institucionální podpora: RVO:61388998
Klíčová slova: flutter oscillations of turbine blades * dry friction * damping of vibration * modes * nodal diameters
Obor OECD: Applied mechanics

Dry-friction damping effect to reduction of self-excited vibrations due to aero-elastic instability is studied on numerical reduced model of rotating turbine wheel with 30 blades. The aerodynamic excitation arises from the spatially periodical flow of steam through the stator blades cascade. Dry friction contact damping is considered as one of the very effective methods for self-excited “flutter” vibrations. The study is oriented on the narrow frequency range and therefore the blades are modelled as systems with one degree of freedom (DOF). The selfexcited aero-elastic forces of blades are described by two different types of Van der Pol model. It is shown for both self-excitation models that the dry friction forces needed for suppression of dangerous flutter vibrations strongly depends on the complexity of modes and also on the mutual positions of excitation forces to damping elements.
Trvalý link: http://hdl.handle.net/11104/0303688