|
|
Turbine blade linkages in reduced modal synthesis model
Pešek, Luděk ; Šnábl, Pavel
The paper is the first stage of our modelling turbine blade linkages in reduced modal synthesis model. The modal synthesis method is used for the dynamic behaviour studies of turbine bladed wheels with frictional inter-blade linkages and in case of the microslips the stiffening effect of the linkages play an important role in wheel dynamics. The paper presents the first results of modal analysis of the wheel when springs were used to substitute the linkages in the modal synthesis model.
|
|
|
The new HPC results of 3D FE modelling of dry-friction damping at tie-boss couplings of bladed wheel - 6nd resonant mode
Pešek, Luděk ; Šnábl, Pavel ; Bula, Vítězslav
The paper is a direct continuation of our study published in the last colloquium DYMAMESI. This paper deals with the new results of dry-friction damping calculation of the bladed wheel with tie-boss couplings vibrating at a higher resonant mode, i.e. mode with 6 nodal diameters (ND). The numerical solution of the wheel based on 3D finite element method with surface-to-surface dry friction contact model is applied. Due to dry friction contacts and non-linear solution, it leads to HPC computations and long computation times. Therefore, the earlier proposed computational strategy for damping evaluation where the resonant attenuation is computed directly from the defined resonant initial conditions given by the 6ND mode is used. Comparison of experimental and numerical results of dynamical behaviour of the bladed wheel yields a reasonable agreement for the studied vibration mode.
|
|
|
Contribution to HPC FEM calculations of bladed disk dynamics with dry-friction contacts
Pešek, Luděk ; Šnábl, Pavel ; Bula, Vítězslav
The experimental set-up for studying dynamical behaviour of the bladed wheel with pre-stressed dry-friction contacts in tie-bosses was built. The numerical solution of the turbine bladed wheel with tie-bosses based on 3D finite element method with surface to surface dry-friction contact model is proposed. Comparison of experimental and preliminary numerical results of dynamical behaviour and damping estimation of our bladed wheel design yielded a reasonable agreement. Due to dry-friction contacts and non-linear solution of 3D FE model it, however, leads to HPC computations and long computation times. The contribution deals with description of computational strategy for damping evaluation and achieved results, too.
|
|
|
Contribution to modelling of bladed model disk with dry-friction contacts in tie-bosses
Pešek, Luděk ; Šnábl, Pavel ; Šulc, Petr ; Půst, Ladislav ; Bula, Vítězslav
The experimental set-up for studying dynamical behavior of the bladed wheel with pre-stressed dry-friction contacts in tie-bosses was built. The numerical solution of the turbine bladed wheel with tiebosses based on 3D finite element method with surface to surface dry friction contact model is proposed. Comparison of experimental and preliminary numerical results of dynamical behavior and damping estimation of our bladed wheel design yielded a reasonable agreement. Limitation of the non-linear solution due to dry friction contacts is HPC computations and long computation times. The contribution will deal with the achieved results.\n
|
|
| |
|
| |
|
|
Příprava, realizace a vyhodnocení experimentu na modelovém zkušebním kole s nosníky a klínovými třecími členy
Pešek, Luděk ; Vaněk, František ; Veselý, Jan ; Bula, Vítězslav ; Procházka, Pavel ; Cibulka, Jan
V prvé části zprávy je popsána příprava a realizace experimentu na modelovém zkušebním kole s nosníky se zabudovanými klínovými třecími členy. Příprava obsahovala osazení modelového oběžného kola tenzometry pro sledování deformací, instalaci senzorů pro sledování pohybu třecích členů za rotace a elektromagnetické buzení pro vybuzení rezonančního kmitání při různých otáčkách. V realizaci experimentu byla zahrnuta modální analýza kola bez a s třecími členy za klidu bez rotace a dále pro vytipované otáčky v rozsahu 60 až 2100 ot/min. Kromě elektromagnetického buzení byly provedeny i experimenty s buzením permanentními magnety. Pro posouzení vlivu třecích členů byla použita srovnávací metoda, kdy byly porovnány výsledky oběžného kola s třecími členy s výsledky kola bez třecích členů při stejných podmínkách zkoušky.
|
host ::
RSS.