Force Characteristics of Rotating Air Film and Flow Closed-Loop for Noncontact Adsorption

A rotating air film is used in a wide range of applications, such as rotating machines, filtering systems, and computer storage devices. In this study, the pressure distribution and force characteristic curve of a rotating air film was both theoretically and experimentally analyzed. First, based on von Kármán's similarity transformation, a theoretical model of the pressure distribution and generation mechanism of suction force of a finite disk was developed by considering the distance of two disks and the edge conditions of the disk. The experimental results showed good agreement with theoretical results. This paper also proposes a new application for the rotating air film, i.e., a noncontact adsorption device, based on the negative feedback closed-loop of force and distance between two disks. The method was investigated and verified theoretically and experimentally, and a force characteristic curve with positive stiffness could be formed. Finally, based on the proposed method, we designed and manufactured an apparatus that can exert suction force on a flat workpiece without contact.