DSpace Kolekce:http://hdl.handle.net/11025/106722024-03-28T21:51:28Z2024-03-28T21:51:28ZPrediction of the nuclear fuel rod abrasionZeman, VladimírHlaváč, Zdeněkhttp://hdl.handle.net/11025/106812021-09-22T08:43:33Z2013-01-01T00:00:00ZNázev: Prediction of the nuclear fuel rod abrasion
Autoři: Zeman, Vladimír; Hlaváč, Zdeněk
Abstrakt: The paper is focused on calculation of the friction forces work in the contact of nuclear fuel rods with fuel assembly spacer grid cells. This friction work is deciding factor for the prediction of the fuel rod coating abrasion. The fuel rod abrasion is caused by fuel assembly vibrations excited by pressure pulsations of the cooling liquid generated by main circulation pumps. A prediction of fuel rod coating abrasion makes use of experimentally investigated dependence of the abrasion on the friction force work in laboratory conditions. The presented original analytical-numerical method is applied for nuclear fuel rod inside of the Russian TVSA-T fuel assembly in the WWER 1000/320 type reactor core in NPP Temelin.2013-01-01T00:00:00ZZeman, VladimírHlaváč, ZdeněkDetermination of the transient vibrations of a rigid rotor attenuated by a semiactive magnetorheological damping device by means of computational modellingZapoměl, JaroslavFerfecki, PetrKozánek, Janhttp://hdl.handle.net/11025/106802021-09-22T08:43:33Z2013-01-01T00:00:00ZNázev: Determination of the transient vibrations of a rigid rotor attenuated by a semiactive magnetorheological damping device by means of computational modelling
Autoři: Zapoměl, Jaroslav; Ferfecki, Petr; Kozánek, Jan
Abstrakt: Unbalance is the principal source of increase of time varying forces transmitted between the rotor and its stationary
part. Their magnitudes can be considerably reduced if th
e rotor is flexibly suspended and if the damping devices
are added to the support elements. Their damping effect mu
st be high for low rotor velocities and small for veloc-
ities approximately higher than the critical one to minimize the transmitted forces and the vibrations amplitude.
This implies to achieve maximum efficiency of the damping elements, their damping effect has to be adaptable to
the current operating conditions. Such technological solutio
n is offered by application of a squeeze film magne-
torheological damper. Its hybrid variant consisting of two damping units (one controllable) in a serial arrangement
is investigated in this paper. The damping takes place in two concentric lubricating films formed by normal and
magnetorheological oils. The damper is equipped with an
electric coil generating magnetic flux passing through
the layer of the magnetorheological fluid. As resistanc
e against its flow depends on magnetic induction, changing
magnitude of the applied current enables to control the damping force. In the computational model, the rotor is
considered to be absolutely rigid, unbalanced and the damping elements are represented by force couplings. The
goal of the analysis is to study influence of the investigated magnetorheological damper on behaviour of a rigid
rotor during different transient reg
imes. A special attention is focused on
passing the rotor through the critical
speed and on planning the dependence of the applied current on speed of the rotor rotation to achieve the optimum
compromise between minimizing the transmitted forces and maximum attenuation of the rotor vibrations.2013-01-01T00:00:00ZZapoměl, JaroslavFerfecki, PetrKozánek, JanTorsional vibration analysis of shafts based on Adomian decomposition methodTabassian, Rassoulhttp://hdl.handle.net/11025/106792021-09-22T08:43:33Z2013-01-01T00:00:00ZNázev: Torsional vibration analysis of shafts based on Adomian decomposition method
Autoři: Tabassian, Rassoul
Abstrakt: In this paper free torsional vibration of shafts is studi
ed using a new approach of solving differential equations
called Adomian decomposition method (ADM). Applying this method to free torsional vibration of shafts means
a systematic and straightforward procedure for calculating both low and high frequency modes. In this paper
different boundary conditions are app
lied to both end of the shaft and firs
t five natural frequencies and mode
shapes are calculated for four different cases. Obtained results are compared with results presented in literature.
These results demonstrate that ADM is a suitable approach for analysis of free torsional vibration of shafts which
provides precise results with high order of accuracy.2013-01-01T00:00:00ZTabassian, RassoulThermal analysis of isotropic plates using hyperbolic shear deformation theoryShinde, B. M.Sayyad, Atteshamuddin ShamshuddinKawade, A. B.http://hdl.handle.net/11025/106782021-09-22T08:43:33Z2013-01-01T00:00:00ZNázev: Thermal analysis of isotropic plates using hyperbolic shear deformation theory
Autoři: Shinde, B. M.; Sayyad, Atteshamuddin Shamshuddin; Kawade, A. B.2013-01-01T00:00:00ZShinde, B. M.Sayyad, Atteshamuddin ShamshuddinKawade, A. B.