skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Cascaded thermoacoustic devices

Abstract

A thermoacoustic device is formed with a resonator system defining at least one region of high specific acoustic impedance in an acoustic wave within the resonator system. A plurality of thermoacoustic units are cascaded together within the region of high specific acoustic impedance, where at least one of the thermoacoustic units is a regenerator unit.

Inventors:
; ;
Publication Date:
Research Org.:
The Regents of the University of California, Los Alamos, NM (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1174607
Patent Number(s):
6,658,862
Application Number:
10/125,268
Assignee:
The Regents of the University of California (Los Alamos, NM) OSTI
DOE Contract Number:
W7405-ENG-36
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING

Citation Formats

Swift, Gregory W., Backhaus, Scott N., and Gardner, David L. Cascaded thermoacoustic devices. United States: N. p., 2003. Web.
Swift, Gregory W., Backhaus, Scott N., & Gardner, David L. Cascaded thermoacoustic devices. United States.
Swift, Gregory W., Backhaus, Scott N., and Gardner, David L. Tue . "Cascaded thermoacoustic devices". United States. doi:. https://www.osti.gov/servlets/purl/1174607.
@article{osti_1174607,
title = {Cascaded thermoacoustic devices},
author = {Swift, Gregory W. and Backhaus, Scott N. and Gardner, David L.},
abstractNote = {A thermoacoustic device is formed with a resonator system defining at least one region of high specific acoustic impedance in an acoustic wave within the resonator system. A plurality of thermoacoustic units are cascaded together within the region of high specific acoustic impedance, where at least one of the thermoacoustic units is a regenerator unit.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Dec 09 00:00:00 EST 2003},
month = {Tue Dec 09 00:00:00 EST 2003}
}

Patent:

Save / Share:
  • An apparatus and method for determining acoustic power density level and its direction in a fluid using a single sensor are disclosed. The preferred embodiment of the apparatus, which is termed a thermoacoustic couple, consists of a stack of thin, spaced apart polymeric plates, selected ones of which include multiple bimetallic thermocouple junctions positioned along opposite end edges thereof. The thermocouple junctions are connected in series in the nature of a thermopile, and are arranged so as to be responsive to small temperature differences between the opposite edges of the plates. The magnitude of the temperature difference, as represented bymore » the magnitude of the electrical potential difference generated by the thermopile, is found to be directly related to the level of acoustic power density in the gas.« less
  • A thermoacoustic device is described having a thermal stack made from a piece of porous material which provides a desirable ratio of thermoacoustic area to viscous area, which has a low resistance to flow, which minimizes acoustic streaming and which has a high specific heat and low thermal conductivity. The thermal stack is easy and cheap to form and it can be formed in small sizes. Specifically, in one embodiment, a thermal stack which is formed by the natural structure of a porous material such as reticulated vitreous carbon is disclosed. The thermal stack is formed by machining a blockmore » of reticulated vitreous carbon into the required shape of the thermal stack. In a second embodiment, a micro-thermoacoustic device is disclosed which includes a thermal stack made of a piece of porous material such as reticulated vitreous carbon. In another embodiment, a heat exchanger is disclosed which is formed of a block of heat conductive open cell foam material. 13 figs.« less
  • A thermoacoustic magnetohydrodynamic electrical generator includes an intrinsically irreversible thermoacoustic heat engine coupled to a magnetohydrodynamic electrical generator. The heat engine includes an electrically conductive liquid metal as the working fluid and includes two heat exchange and thermoacoustic structure assemblies which drive the liquid in a push-pull arrangement to cause the liquid metal to oscillate at a resonant acoustic frequency on the order of 1,000 Hz. The engine is positioned in the field of a magnet and is oriented such that the liquid metal oscillates in a direction orthogonal to the field of the magnet, whereby an alternating electrical potentialmore » is generated in the liquid metal. Low-loss, low-inductance electrical conductors electrically connected to opposite sides of the liquid metal conduct an output signal to a transformer adapted to convert the low-voltage, high-current output signal to a more usable higher voltage, lower current signal.« less
  • 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 themore » 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.« less
  • A thermoacoustic device having a thermal stack made from a piece of porous material which provides a desirable ratio of thermoacoustic area to viscous area, which has a low resistance to flow, which minimizes acoustic streaming and which has a high specific heat and low thermal conductivity is disclosed. The thermal stack is easy and cheap to form and it can be formed in small sizes. Specifically, in one embodiment, a thermal stack which is formed by the natural structure of a porous material such as reticulated vitreous carbon is disclosed. The thermal stack is formed by machining a blockmore » of reticulated vitreous carbon into the required shape of the thermal stack. In a second embodiment, a micro-thermoacoustic device is disclosed which includes a thermal stack made of a piece of porous material such as reticulated vitreous carbon. In another embodiment, a heat exchanger is disclosed which is formed of a block of heat conductive open cell foam material.« less