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Výpočet dynamických vlastností aerostatických ložisek
Skarolek, A. ; Kozánek, Jan
This contribution deals with computation of stiffness and damping coefficients of aerostatic bearings. Model of bearings is based on Reynolds equation for compressible medium supplemented by descrition of mass flow through feeding system. Time-series of displacements and internal forces are obtained by numerical solution. Linear stiffness and damping coefficients are obtained by means of least squares regression.
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Pohyb rotoru uloženého v aerodynamických ložiskách
Půst, Ladislav ; Šimek, J. ; Kozánek, Jan
The tilting pad bearings are very often applied in high speed rotating machines. The exact solution of bearing characteristics, including the motion of tilting pads, is very difficult and not yet completely elaborated. an approximate method for calculattion of rigid rotor motion with large amplitudes limited only by the bearing clearance is presented. The models of stiffness and damping forces valid for the entire area of journal motion in the aerodynamic bearingś clearance are based on the transformation of linear stiffness and damping characteristics calculated for two cases of stationary state and extended to the whole bearing field by using the correction function fc(r). Differential equations of motion of rigid rotor supported on two aerodynamic bearings with proposed nonlinear characteristics are numerically solved and resulting time histories of journal motion, their plane trajectories will be presented.
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Identification and reconstruction of non-conservative system
Kozánek, Jan ; Mazúch, T.
Identification and reconstruction of non-conservative system. The identification (via least squares smoothing method of the transfer function) and the reconstuction of laboratory dynamic systems with the accent to the so-called condensability condition are considered. It enables one to reconstuct spectrally and modally faithful coefficient matrices of vibrating systems. Various reconstruction approaches are compared each to other.
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