Ralph E Marrs

US Patent:

43507247, Sep 21, 1982

Filed:

May 9, 1980

Appl. No.:

6/148482

Inventors:

Ralph E. Marrs - San Jose CA

International Classification:

B32B 300
G10K 1100

US Classification:

428 69

Abstract:

A passive system having high volumetric compliance in response to compressions and expansions, such as are present in low frequency acoustic wave energy, employs a saturated vapor-saturated liquid interface thermodynamically stabilized by distributed heat sinks that interact with the acoustic wave energy. The volumetric compliance of a system, such as a loudspeaker enclosure, is significantly increased by utilizing a spatially distributed mass of fine fibers thoroughly wetted by a liquid, to provide thin liquid sheaths on the fibers that are in good thermal interchange with the fibers themselves and also with the vapor molecules in the spaces between the fibers. The liquid preferably has a low heat of vaporization, a high vapor pressure at the ambient temperature and a low rate of pressure change with respect to temperature. The liquid sheaths and fibers serve as high surface area heat sinks having a short thermal transport distance to supply the alternating heat attendant to evaporation and condensation. The fiber masses are preferably disposed in thin layers separated by communicating channels, so that the interaction takes place substantially uniformly within the volume occupied by the fibers, without substantial dissipation of energy in any concentrated region.

US Patent:

44509294, May 29, 1984

Filed:

Sep 7, 1982

Appl. No.:

6/415190

Inventors:

Ralph E. Marrs - San Jose CA

International Classification:

H05K 500

US Classification:

181146

Abstract:

A passive system having high volumetric compliance in response to compressions and expansions, such as are present in low frequency acoustic wave energy, employs a saturated vapor-saturated liquid interface thermodynamically stabilized by distributed heat sinks that interact with the acoustic wave energy. The volumetric compliance of a system, such as a loudspeaker enclosure, is significantly increased by utilizing a spatially distributed mass of fine fibers thoroughly wetted by a liquid, to provide thin liquid sheaths on the fibers that are in good thermal interchange with the fibers themselves and also with the vapor molecules in the spaces between the fibers. The liquid preferably has a low heat of vaporization, a high vapor pressure at the ambient temperature and a low rate of pressure change with respect to temperature. The liquid sheaths and fibers serve as high surface area heat sinks having a short thermal transport distance to supply the alternating heat attendant to evaporation and condensation. The fiber masses are preferably disposed in thin layers separated by communicating channels, so that the interaction takes place substantially uniformly within the volume occupied by the fibers, without substantial dissipation of energy in any concentrated region.