Liquid metal thermoacoustic engine

Conference · Wed Jan 01 00:00:00 EST 1986

DOI:https://doi.org/10.1121/1.2023216· OSTI ID:5625945

Swift, G W; Migliori, A; Wheatley, J C

We are studying a liquid metal thermoacoustic engine both theoretically and experimentally. This type of engine promises to produce large quantities of electrical energy from heat at modest efficiency with no moving parts. A sound wave is usually thought of as consisting of pressure oscillations, but always attendant to the pressure oscillation are temperature oscillations. The combination produces a rich variety of ''thermoacoustic'' effects. These effects are usually so small that they are never noticed in everyday life; nevertheless under the right circumstances they can be harnessed to produce powerful heat engines, heat pumps, and refrigerators. In our liquid metal thermoacoustic engine, heat flow from a high temperature source to a low temperature sink generates a high-amplitude standing acoustic wave in liquid sodium. This acoustic power is converted to electric power by a simple magnetohydrodynamic effect at the acoustic oscillation frequency. We have developed a detailed thermoacoustic theory applicable to this engine, and find that a reasonably designed liquid sodium engine operating between 700/sup 0/C and 100/sup 0/C should generate about 60 W/cm/sup 2/ of acoustic power at about 1/3 of Carnot's efficiency. Construction of a 3000 W-thermal laboratory model engine has just been completed, and we have exciting preliminary experimental results as of the time of preparation of this manuscript showing, basically, that the engine works. We have also designed and built a 1 kHz liquid sodium magnetohydrodynamic generator and have extensive measurements on it. It is now very well characterized both experimentally and theoretically. The first generator of its kind, it already converts acoustic power to electric power with 40% efficiency. 16 refs., 5 figs.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5625945
• Report Number(s): LA-UR-86-1548; CONF-860810-6; ON: DE86011264
• Resource Relation: Journal Volume: 79; Journal Issue: S1; Conference: Intersociety energy conversion engineering conference, San Diego, CA, USA, 25 Aug 1986; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
DIRECT ENERGY CONVERSION
ENERGY LOSSES
THERMAL EFFICIENCY
LIQUID METALS
SOUND WAVES
BENCH-SCALE EXPERIMENTS
ELECTRIC POWER
ENERGY CONVERSION
MAGNETOHYDRODYNAMICS
OSCILLATIONS
SODIUM
THERMAL CONDUCTIVITY
VISCOSITY
ALKALI METALS
CONVERSION
EFFICIENCY
ELEMENTS
FLUID MECHANICS
FLUIDS
HYDRODYNAMICS
LIQUIDS
LOSSES
MECHANICS
METALS
PHYSICAL PROPERTIES
POWER
THERMODYNAMIC PROPERTIES
425000* - Engineering- Power Cycles- (1980-)