A resonantly-coupled ��-Stirling (RCAS) cooler was designed and constructed.
Tests on air and helium were performed with constant driving displacement over a range
of frequencies. The effects of changing driving amplitude and charged pressure were
studied.
The use of stainless steel bellows in place of pistons eliminated the problem of
piston seals and relaxed the construction tolerances. The fatigue life of the bellow is,
however, a problem. The experimental optimization based on Taguchi methods was
performed on regenerator mass, regenerator wire diameter, vibrating mass, and damping
coefficient.
Driven by a voice coil actuator, the characteristic phase shift of the Stirling cycle
cooler was demonstrated where the hot-end displacement led the cold-end displacement.
The 90�� phase shift was selected as the natural frequency.
The pressure-volume diagrams for each working space were plotted and the
indicated powers were determined. The compression powers in the hot and cold-ends
show maximum values near the natural frequency. The mechanisms are different. At the
hot-end where the displacement was kept constant, operation near the natural frequency
gave a maximum pressure ratio and also maximized the compression power. The phase
shifts in the cold-end were, however, relatively constant. The maximum pressure ratio
and amplitude gave the maximum expansion power near the natural frequency.
The expansion powers in the cold-end as indicators of cooling potential were
approximately 2-4 watts for the air case, and 3-7 watts for the helium case. In both air and helium tests, the value of the parasitic losses reached 12 watts.
The temperature difference developed across the regenerator is considered an indication of the cooling capacity. Good correlations were found between the indicated cooling capacity in the expansion space and the temperature difference.
For a given size of cooler, the use of helium offered higher cooling capacity due to smaller pressure drop loss and smaller amplitude ratio. Higher cooling performance was also attained from helium at elevated pressures. / Graduation date: 1998
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/34518 |
| Date | 01 December 1997 |
| Creators | Sripakagorn, Paiboon |
| Contributors | Peterson, Richard B. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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