The Gas Squeeze Film Characteristics of Acoustic Levitation with Various Excitation Disc Shapes Based on the Modified Reynolds Equation

Abstract

In order to simulate the characteristics of acoustic levitation for freely floating states with a larger ratio between the excitation radius and film thickness, a group of governing equations including a modified Reynolds, movement, and vibration equations were derived in this article. The inertia effect was considered in the modified Reynolds equation (MRE) and compared to experimental vibration curves. The vibration curves were interpolated from the experimental data on disc modal shapes with the standing wave’s excitation. The effect of wave numbers and amplitudes on floating height and bearing capacity are discussed in this article. The results indicate that the amplitudes of the excitation disc are approximately linear with the floating height, and the larger wave number along R direction can induce not only better bearing capacity but also floating stability. It is concluded that there would be more accurate results for floating height calculated by the MRE considering inertia effects. This squeeze film model with the MRE can aid in the design of actuators.

Keywords:

• Squeeze film lubrication
• inertia effects
• MEMS devices

Acknowledgements

The authors are grateful to Tomohiro Sho and Koshiro Nishikawa lab work performed in the original experimental reference. The authors also express their appreciation to Professor Izhak Bucher of the Israel Institute of Technology and Professor Mark Atherton and Professor Tadeusz Stolarski of Brunel University, who provided significant guidance in both theory and experiments.

Additional information

Funding

This research was funded by the National Natural Science Foundation of China (51605250) and Natural Science Foundation of Beijing Municipality (3192024).