Study on Transient Properties of Levitated Object in Near-Field Acoustic Levitation

• Published in: Communications in theoretical physics Vol. 56; no. 12; pp. 1119 - 1124
• Main Author: 贾兵 陈超 赵淳生
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.12.2011
• Subjects: Acoustic levitation; Algebra; Amplitudes; Boundaries; Mathematical analysis; Mathematical models; Numerical analysis; Oscillations; 响应时间; 声悬浮; 径向速度; 控制方程; 瞬态响应特性; 瞬态特性; 磁悬浮; 近场
• ISSN: 0253-6102
• DOI: 10.1088/0253-6102/56/6/25

A new approach to the study on the transient properties of the levitated object in near-field acoustic levitation （NFAL） is presented. In this article, the transient response characteristics, including the levitated height of an object with radius of 24 mm and thickness of 5 mm, the radial velocity and pressure difference of gas at the boundary of clearance between the levitated object and radiating surface （squeeze film）, is calculated according to severa/velocity amplitudes of radiating surface. First, the basic equations in fluid areas on Arbitrary Lagrange--Euler （ALE） form are numericaJly solved by using streamline upwind petrov gaJerkin （SUPG） finite elements method. Second, the formed a/gebraic equations and solid control equations are solved by using synchronous alternating method to gain the transient messages of the levitated object and gas in the squeeze film. Through theoretical and numerical analyses, it is found that there is a oscillation time in the transient process and that the response time does not simply increase with the increasing of velocity amplitudes of radiating surface. More investigations in this paper are helpful for the understanding of the transient properties of levitated object in NFAL, which are in favor of enhancing stabilities and responsiveness of levitated object.