Análise comparativa de modelos de levitação acústica de campo próximo

Abstract

The acoustic levitation methodology is an alternative for applications where there is a need to reduce mechanical resistance, either by reducing friction to reduce the effect of heat generated and maximizing performance, or when using it for products where it is required purity or undamaged components. Like all kinds of levitation, the concept is to promote a force contrary to the gravitational force of the object, so that it is suspended (or levitated). It is possible to establish some methods to generate such force, among them the aerodynamics (force promoted by the air), the electrostatic (force promoted by the electric field), the magnetic (force promoted by the magnetic field) and the optical (force promoted by lasers and lenses). In acoustics, in particular, the force is generated by a pressure field through a vibrating surface, and this levitation technique is classified into two types: flat waves and near field levitation. In this work we will approach the near-field acoustic levitation method, where a comparison will be made between the pressure fields created under different conditions (by varying the compression number and the vibration amplitude of the driving surface, in addition to the condition of the object being fixed or free), establishing the observation and analysis between two different numerical methodologies (between the Reynolds equation methodology, implemented through the partial differential equation solution in MATLAB® software and the COMSOL Multiphysics® software methodology, based on Reynolds and Euler equations).