scholarly journals Modelling and nonlinear dynamic behavior of a geared rotor-bearing system using tooth surface microscopic features based on fractal theory

AIP Advances ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 015201
Author(s):  
Qi Chen ◽  
Jianjun Zhou ◽  
Ammar Khushnood ◽  
Yanming Wu ◽  
Yan Zhang
Keyword(s):  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
Fractal Theory ◽  
Tooth Surface ◽  
Rotor Bearing ◽  
Nonlinear Dynamic Behavior ◽  
Microscopic Features ◽  
Bearing System

Nonlinear Dynamic Behavior of a Rotor Bearing System With Nonlinear Viscous Damping Suspension

2017 ◽  
Author(s):  
Shuai Yan ◽  
Bin Lin ◽  
Jixiong Fei ◽  
Pengfei Liu
Keyword(s):  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
Vibration Isolation ◽  
Lubricating Oil ◽  
Viscous Damping ◽  
Oil Viscosity ◽  
Speed Range ◽  
Rotor Bearing ◽  
Nonlinear Dynamic Behavior ◽  
Bearing System

Nonlinear damping suspension has gained attention owing to its excellent vibration isolation performance. In this paper, a cubic nonlinear viscous damping suspension was introduced to a rotor bearing system for vibration isolation between the bearing and environment. The nonlinear dynamic response of the rotor bearing system was investigated thoroughly. First, the nonlinear oil film force was solved based short bearing approximation and half Sommerfeld boundary condition. Then the motion equations of the system was built considering the cubic nonlinear viscous damping. A computational method was used to solve the equations of motion, and the bifurcation diagrams were used to display the motions. The influences of rotor-bearing system parameters were discussed from the results of numerical calculation, including the eccentricity, mass, stiffness, damping and lubricating oil viscosity. The results showed that: (1) medium eccentricity shows a wider stable speed range; (2) rotor damping has little effect to the stability of the system; (3) lower mass ratio produces a stable response; (4) medium suspension/journal stiffness ratio contributes to a wider stable speed range; (5) a higher viscosity shows a wider stable speed range than lower viscosity. From the above results, the rotor bearing system shows complex nonlinear dynamic behavior with nonlinear viscous damping. These results will be helpful to carrying out the optimal design of the rotor bearing system.

Study on Bifurcation of Rigid Rotor Roller Bearings System Considering Nonlinear Dynamic Behavior

2010 ◽  
Vol 34-35 ◽  
pp. 467-471
Author(s):  
Li Cui ◽  
Jian Rong Zheng
Keyword(s):  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
Roller Bearing ◽  
Radial Clearance ◽  
Rigid Rotor ◽  
Rotating Speed ◽  
Rotor Bearing ◽  
Nonlinear Dynamic Behavior ◽  
Bifurcation And Stability ◽  
Bearing System

Rigid rotor roller bearing system displays complicated nonlinear dynamic behavior due to nonlinear Hertzian force of bearing. Nonlinear bearing forces of roller bearing and dynamic equations of rotor bearing system are established. The bifurcation and stability of the periodic motion of the system in radial clearance-rotating speed and ellipticity-rotating speed parametric domains are studied by use of continuation-shooting algorithm for periodic solutions of nonlinear non-autonomous dynamics system. Results show that the parameters of rotor bearing system should be designed carefully in order to obtain period-1 motion.

scholarly journals Nonlinear Dynamic Behavior of Double-Disk Isotropic Rotor System with Axial Rub-Impact

2011 ◽  
Vol 2-3 ◽  
pp. 678-682
Author(s):  
Y. Zhang ◽  
W.M. Wang ◽  
J.F. Yao
Keyword(s):  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
High Speed ◽  
Element Model ◽  
Rotor System ◽  
Self Healing ◽  
Rotor Bearing ◽  
Nonlinear Dynamic Behavior ◽  
Operation Stability ◽  
Bearing System

In the case of considering the shear effect and gyroscopic effect, a finite element model is developed to study the nonlinear dynamic behavior of a double-disk isotropic rotor- bearing system with axial rub-impact in this paper. The influences of rotational speed and initial phase difference on the operation stability of the rotor-bearing system are discussed. It transpires that the response of the rotor system with axial rub- impact is mainly synchronous periodic motion. The vibration signals of axial rub-impact include such as the synchronous signal and the multiple frequencies, in which the synchronous signal is dominating signal. There is no weakening wave phenomenon in time wave plot. All the results are in reasonable good agreement with those observed in engineering. The results of this paper could provide certain reference for fault diagnosis and self-healing of large high-speed rotating machinery system, thus ensuring the safe operation of the system.

Nonlinear Dynamic Behavior of Rotor-Bearing Systems Involving Two Hydrodynamic Oil Films in Series: Prediction and Test Application to High-Speed Turbochargers

2006 ◽  
Author(s):  
Kostandin Gjika ◽  
Chris Groves
Keyword(s):  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
High Speed ◽  
High Performance ◽  
Maximum Speed ◽  
Inlet Temperature ◽  
Oil Viscosity ◽  
Rotor Bearing ◽  
Nonlinear Dynamic Behavior ◽  
Bearing System

In recent years, the desire for increased engine performance has led to technology that increasingly relies on robust and reliable turbocharging solutions. The rotor-bearing system (RBS) operates under extreme oil conditions of low viscosity, high temperatures, low HTHS (high temperature high shear) value and low pressure, while the demand for maximum turbocharger speed and variable geometry technology continues to increase. The rotordynamics instability is a potential issue and the development of RBS is becoming a challenge for design optimization at the development stage. It is further complicated by a lack of industrial standards to guide design practices related to the dynamics and the effort to combine high performance with low cost. This paper concerns the progress on nonlinear dynamic behavior modeling of turbocharger rotor-radial bearing system with fully floating bearing design. A developed fluid dynamics code predicts bearing rotational speed, operating inner and outer bearing clearances, effective oil viscosity taking into account the shear effect and hydrostatic load. The data are input to a rotordynamics code which predicts nonlinear lateral response (total shaft motion) of the rotor-bearing system. The model is validated with a high speed turbocharger RBS of 7.9 mm journal diameter running up to 160,000 rpm (maximum speed) with oil 0W30, 100 °C oil inlet temperature and 4 bar oil feed pressure. The test is conducted on a rotordynamics technology cell. An advanced data acquisition system is implanted and a powerful code is developed for automated data reduction. Prediction/test data show good correlation with the respect of synchronous response and total motion. The predictive model helps the development of high performance RBS with faster development cycle times and increased reliability.

On the Nonlinear Dynamic Behavior of a Rotor-Bearing System

2002 ◽  
Author(s):  
Jianping Jing ◽  
Yi Sun ◽  
Songbo Xia ◽  
Guotai Feng
Keyword(s):  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
Rotor System ◽  
Careful Examination ◽  
Mode Superposition Method ◽  
Direct Integration Method ◽  
Oil Whirl ◽  
Rotor Bearing ◽  
Nonlinear Dynamic Behavior ◽  
Bearing System

The nonlinear dynamic behavior of a rotor-bearing system is analyzed based on a continuum model. The finite element method is adopted in the analysis. Emphasis is given on the so called “Oil-Whirl phenomena” which might lead to the failure of the rotor system. The dynamic response of the system in unbalanced condition is approached by direct integration method and mode superposition method, it is found that a typical “Oil-Whirl phenomenon” is successfully produced. Furthermore, the bifurcation behavior of the Oil-Whirl phenomenon that is much concerned in recent nonlinear dynamics research is analyzed. The rotor-bearing system is also examined by the simple discrete model. Significant differences are found between these two models. It is suggested that a careful examination should be made in modeling such nonlinear dynamic behavior of the rotor system.

Nonlinear Dynamic Behavior of Turbocharger Rotor-Bearing Systems With Hydrodynamic Oil Film and Squeeze Film Damper in Series: Prediction and Experiment

2010 ◽  
Vol 5 (4) ◽  
Author(s):  
K. Gjika ◽  
L. San Andrés ◽  
G. D. Larue
Keyword(s):  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
High Performance ◽  
Squeeze Film ◽  
Inlet Temperature ◽  
Squeeze Film Damper ◽  
Feed Pressure ◽  
Nonlinear Dynamic Behavior ◽  
In Series ◽  
Bearing System

Current trends for advanced automotive engines focusing on downsizing, better fuel efficiency, and lower emissions have led to several changes in turbocharger bearing system design and technology. Automotive turbochargers run faster and use engine oils with very low viscosity under high oil inlet temperature and low feed pressure. The development of high performing bearing systems, marrying innovation with reliability, is a persistent challenge. This paper shows progress on the nonlinear dynamic behavior modeling of the rotor-radial bearing system (RBS) incorporating two oil films in series: a hydrodynamic one with a squeeze film damper commonly used in turbochargers. The developed fluid bearing code predicts bearing rotational speed (in the case of fully floating design), operating inner and outer bearing film clearances, effective oil viscosity, taking into account its shear effect, and hydrostatic load. A rotordynamics code uses this input to predict the nonlinear lateral dynamic response of the rotor-bearing system. The model predictions are validated with test data acquired on a high speed turbocharger RBS of a 6.0 mm journal diameter running up to 250,000 rpm (maximum speed), 5W30 oil type, 150°C oil inlet temperature, and 4 bar oil feed pressure. The tests are conducted at a rotordynamics technology laboratory using a high performance data acquisition system. Turbochargers with four combinations of inner and outer RBS clearances are tested. Prediction and measured synchronous response and total motion are in good agreement. Both demonstrate the nonlinear character of the RBS behavior, including several subsynchronous frequency components across the operating speed range. The nonlinear predictive model aids the development of high performance and optimized turbocharger RBS with faster development cycle times and increased reliability.

Nonlinear Dynamic Behavior of Turbocharger Rotor-Bearing Systems With Hydrodynamic Oil Film and Squeeze Film Damper in Series: Prediction and Experiment

2007 ◽  
Author(s):  
Kostandin Gjika ◽  
Chris Groves ◽  
Luis San Andre´s ◽  
Gerald D. LaRue
Keyword(s):  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
High Performance ◽  
Squeeze Film ◽  
Inlet Temperature ◽  
Squeeze Film Damper ◽  
Feed Pressure ◽  
Nonlinear Dynamic Behavior ◽  
In Series ◽  
Bearing System

Current trends for advanced automotive engines focusing on downsizing, better fuel efficiency and lower emissions have led to several changes in turbocharger bearing systems design and technology. Automotive turbochargers run faster and use engine oils with very low viscosity under high oil inlet temperature and low feed pressure. The development of high performing bearing systems, marrying innovation with reliability, is a persistent challenge. This paper shows progress on the nonlinear dynamic behavior modeling of rotor-radial bearing system (RBS) incorporating two oil films in series: a hydrodynamic one with a squeeze film damper commonly used in turbochargers. The developed fluid bearing code predicts bearing rotational speed (in case of fully floating design), operating inner and outer bearing film clearances, effective oil viscosity taking into account its shear effect, and hydrostatic load. A rotordynamics code uses this input to predict the nonlinear lateral dynamic response of the rotor-bearing system. The model predictions are validated with test data acquired on a high speed turbocharger RBS of 6.0 mm journal diameter running up to 250,000 rpm (maximum speed), 5W30 oil type, 150 °C oil inlet temperature, and 4 bar oil feed pressure. The tests are conducted at a rotordynamics technology laboratory using a high performance data acquisition system. Turbochargers with four combinations of inner and outer RBS clearances are tested. Prediction and measured synchronous response and total motion are in good agreement. Both demonstrate the nonlinear character of RBS behavior including several subsynchronous frequencies components across the operating speed range. The non linear predictive model aids the development of high performance and optimized turbocharger RBS with faster development cycle times and increased reliability.

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