High temperature acoustic levitator

US4463606A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventor

• Martin B. Barmatz · La Cañada Flintridge, US

Key dates

• Filing date: Aug 26, 1983
• Grant date: Aug 7, 1984
• Expiry date: Aug 26, 2003

Classification

• Technology area (CPC G): Physics
• CPC primary: G10K15/00
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A system is described for acoustically levitating an object (12, FIG. 1) within a portion of a chamber (14) that is heated to a high temperature, while a driver (22) at the opposite end of the chamber is maintained at a relatively low temperature. The cold end of the chamber is constructed so it can be telescoped to vary the length (L.sub.1) of the cold end portion and therefore of the entire chamber, so that the chamber remains resonant to a normal mode frequency, and so that the pressure at the hot end of the chamber is maximized. The precise length of the chamber at any given time, is maintained at an optimum resonant length by a feedback loop. The feedback loop includes an acoustic pressure sensor (42) at the hot end of the chamber, which delivers its output to a control circuit (44), which controls a motor (36) that varies the length (L) of the chamber to a level where the sensed acoustic pressure is a maximum.