Liquid metal thermoacoustic engine

Conference · Wed Jan 01 04:00:00 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 Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5625945
• Report Number(s): LA-UR-86-1548; CONF-860810-6; ON: DE86011264
• Country of Publication: United States
• Language: English

Related Subjects

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