Accession Number : ADA311750

Title :   Improved Efficiency and Power Density for Thermoacoustic Coolers.

Descriptive Note : Technical rept. 1 Jun 95-31 May 96,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF PHYSICS

Personal Author(s) : Hofler, Thomas J.

PDF Url : ADA311750

Report Date : JUN 1996

Pagination or Media Count : 14

Abstract : Work continues on building a thermoacoustic heat driven cooler having no moving parts, with cooling power in the 0.5 to 1.0 kW range. Previous work dealt with numerical modeling of a new engine topology used in the above engine and various work on improved heat exchangers. Recently, morn modeling suggests that cooling powers in the range of 35 kW (10 ton) may be possible with an engine having a longest dimension of 4 ft. and that efficiency improves significantly with size. Also, we have solved some fabrication problems with our high temperature nickel heat exchangers. The major work this year has been on the high temperature thermoacoustic stack structure. A common Stirling engine regenerator structure consisting of stacked disks cut from stainless steel wire mesh was tested in an apparatus previously used for high amplitude heat exchanger measurements. Stacks are very easy to construct in this fashion and longitudinal thermal conduction is greatly reduced. Results show that amplitude performance is very good and within 10% of the usual spiral roll structures. More impressively, the efficiency of the mesh stack is as much as 30% higher than for spiral rolls stacks. We are also conducting measurements on pure carbon random structures that could be used at extremely high temperatures.

Descriptors :   *REFRIGERATION SYSTEMS, HEAT TRANSFER, MATHEMATICAL MODELS, FABRICATION, STAINLESS STEEL, HEAT EXCHANGERS, COOLING, TOPOLOGY, THERMAL CONDUCTIVITY, CRYOGENICS, STACKING.

Subject Categories : Air Condition, Heating, Lighting & Ventilating

Distribution Statement : APPROVED FOR PUBLIC RELEASE