scholarly journals Review of Research on Nonlinear Rotordynamics in Japan

2013 ◽  
Vol 7 (2) ◽  
pp. 151-169 ◽  
Author(s):  
Yukio ISHIDA
2009 ◽  
Vol 57 (4) ◽  
pp. 479-479
Author(s):  
Jörg Wauer ◽  
Yukio Ishida

Author(s):  
Luis San Andre´s ◽  
Juan Carlos Rivadeneira ◽  
Murali Chinta ◽  
Kostandin Gjika ◽  
Gerry LaRue

Passenger vehicle turbochargers (TCs) offer increased engine power and efficiency in an ever-competitive marketplace. Turbochargers operate at high rotational speeds and use engine oil to lubricate fluid film bearing supports (radial and axial). However, TCs are prone to large amplitudes of sub-synchronous shaft motion over wide ranges of their operating speed. Linear rotordynamic tools cannot predict the amplitudes and multiple frequency shaft motions. A comprehensive nonlinear rotordynamics model coupled to a complete fluid-film-bearing model solves in real time the dynamics of automotive turbochargers. The computational design tool predicts the limit cycle response for several inner and outer film clearances and operating conditions including rotor speed and lubricant feed pressure. Substantial savings in product development and prototype testing are the benefits of the present development. The paper presents predictions of the linear and nonlinear shaft motion of an automotive turbocharger supported on a semi-floating ring bearing. The shaft motion predictions are compared to measurements of shaft motion at the compressor nose for speeds up to 240 krpm, and for lubricant inlet pressure of 4 bar at 150°C. Linear and nonlinear rotordynamic models reproduce very well the test data for synchronous response to imbalance. The nonlinear results show two sub-synchronous whirl frequencies whose large magnitudes agree well with the measurements. A large side load predicted for this turbocharger must be considered for accurate prediction of the rotordynamic response.


2011 ◽  
Vol 35 (5) ◽  
pp. 2145-2159 ◽  
Author(s):  
Muhammad Rizwan Shad ◽  
Guilhem Michon ◽  
Alain Berlioz

2007 ◽  
Vol 129 (2) ◽  
pp. 488 ◽  
Author(s):  
Luis San Andrés ◽  
Juan Carlos Rivadeneira ◽  
Murali Chinta ◽  
Kostandin Gjika ◽  
Gerry LaRue

Author(s):  
Bram L. van de Vrande ◽  
Bram de Kraker

Abstract This paper presents the influence of bearing liner compliance on the long-term dynamics of a symmetric rigid rotor on short journal-bearings. Both balanced and unbalanced rotors are investigated for different values of the compliance, using the (nondimensional) rotor speed as the bifurcation parameter. The results show a decrease in the onset speed of instability of the balanced rotor, and a considerable influence on the 1/2-subharmonic solutions in case of unbalance excitation.


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