Gregory M Swift

US Patent:

54560829, Oct 10, 1995

Filed:

Jun 16, 1994

Appl. No.:

8/261361

Inventors:

Robert M. Keolian - Monterey CA
Gregory W. Swift - Santa Fe NM

Assignee:

The Regents of the University of California - Alameda CA

International Classification:

F25B 900

US Classification:

62 6

Abstract:

A thermoacoustic stack for connecting two heat exchangers in a thermoacoustic energy converter provides a convex fluid-solid interface in a plane perpendicular to an axis for acoustic oscillation of fluid between the two heat exchangers. The convex surfaces increase the ratio of the fluid volume in the effective thermoacoustic volume that is displaced from the convex surface to the fluid volume that is adjacent the surface within which viscous energy losses occur. Increasing the volume ratio results in an increase in the ratio of transferred thermal energy to viscous energy losses, with a concomitant increase in operating efficiency of the thermoacoustic converter. The convex surfaces may be easily provided by a pin array having elements arranged parallel to the direction of acoustic oscillations and with effective radial dimensions much smaller than the thicknesses of the viscous energy loss and thermoacoustic energy transfer volumes.