Investigation of non-contact bearing systems based on ultrasonic levitation / Su Zhao. 2010
Inhalt
- 1 Motivation
- 2 State of the art
- 2.1 Non-contact bearings
- 2.2 Ultrasonic levitation
- 2.3 Non-contact bearings using squeeze film ultrasonic levitation
- 3 Research objective and thesis outline
- 4 Basic theory on acoustics
- 4.1 Linear theory
- 4.1.1 Elastic waves in fluids
- 4.1.2 Equations of linear acoustics
- 4.1.3 Acoustic energy density and intensity
- 4.1.4 Atmosphere absorption of sound wave
- 4.2 Nonlinear theory - acoustic radiation pressure
- 5 Piezoelectric ultrasonic transducers
- 6 Standing wave ultrasonic levitation
- 6.1 A configuration for large planar objects
- 6.2 Modeling the proposed levitation system
- 6.2.1 Flexural vibration mode of the radiator
- 6.2.2 Sound beam in the acoustic near-field
- 6.2.3 Increased absorption due to nonlinear effects
- 6.2.4 Modeling the sound field
- 6.3 Simulation results
- 6.4 Conclusion
- 7 Suspension of large planar objects using ultrasonic standing waves
- 7.1 Experiments
- 7.1.1 Experimental setup
- 7.1.2 Levitation force measurement
- 7.1.3 Levitating a compact disc
- 7.1.4 Sound field visualization
- 7.2 Results and discussion
- 7.3 Conclusion
- 8 Squeeze film ultrasonic levitation
- 8.1 Modeling based on acoustic theory - acoustic radiation pressure
- 8.2 Modeling based on fluid mechanics - solving the Reynolds equation
- 8.2.1 Approximate solution of the Reynolds equation for large squeeze number
- 8.2.2 Solving the Reynolds equation numerically
- 8.3 Results and discussion
- 9 An non-contact journal bearing based on squeeze film ultrasonic levitation
- 10 Summary and outlook
- Bibliography