SBIR-STTR Award

The objective of this program is to demonstrate and miniaturize a new type of cryogenic expander, thermoacoustic expander (TAE), for space cryocoolers which provide the cooling power less than 50 mW and operate in the low temperature range between 40K and 10K for cooling SWIR, MWIR, and LWIR surveillance and interceptor systems. TAEs employ high energy acoustic waves generated with absolutely no mechanical moving parts at the cold expander to produce efficient cooling over a wide temperature range. The TAE can replace more conventional complex mechanical moving part turbines or piston expanders as well as Joule Thomson expanders. The novel expander is applicable to cooling multiple sensors or focal planes especially if they must be vibrationally decoupled from the host vehicle, and allowes for efficient integration of a low mass cold head with remote and/or numerous objects to be cooled. In phase I, a proof of concept unit will be designed, fabricated and tested.

Keywords:
Thermoacoustic Expander, Cryogenic Gas Expansion, Recuperative Coolers, Acoustic Wave System, Pressure Expansion, Acoustic Streaming

The objective of this project is to develop a novel expander that can increase the efficiency of cryocoolers for IR sensors at very low temperatures and in remote cooling and across gimbal applications. Miniature Thermoacoustic Expanders (MTAE) that employ high energy acoustic waves generated with no moving parts at the cold expander to produce efficient cooling over a wide range of temperatures and reject heat to much higher temperature level. Unlike JT expanders which are irreversible and limited by their working gas to narrow temperature ranges and typically high pressure ratios, MTAE’s can provide effective cooling for a range of applications even including nanoelectronic components that require very low cooling power for which conventional mechanical turbo or piston expanders are inefficient. MTAE development in Phase II will further extend the technology envelope to smaller scale prototypes and the lower operating temperature range. Successful completion of Phase II will result in the fabrication, test, and delivery of a MTAE prototype unit which is designed for a recuperative cryocooler operating with >1W of cooling power below 77K.

Keywords:
Thermoacoustics, Resonant Tube, Cryogenic Expanders, Recuperative Coolers, Gaseous Wave System, Pressure Expansion