Numerical Analysis of the Nonlinear Restoring Force Based on Near- field Acoustic Levitation
* Presenting author
The stability of the floating object is a key factor in near-field acoustic levitation, which has an extensive application prospect in manufacturing of micro-electromechanical system parts. This study presents a numerical study of the restoring force based on the theory of gas film lubrication. Owing to the eccentricity of the levitator, the gas film in the radiator coordinate is discontinuous. Thus, a finite difference scheme is used to solve the Reynolds equation considering the movement of levitator and to obtain the air pressure distribution. After a coordinate transformation, the restoring force which acts on the levitator can be acquired. An experimental rig is constructed to measure the restoring force with different eccentricity. The experimental results show that the restoring force increases with the increase of eccentricity, which shows very good agreement with numerical results. The predictions indicate that with the increase of the amplitude and the weight of the levitator, the restoring force also increases, which leads to a higher stability of the system.