Master of Science
A cryogenic refrigerator using an expander with a reciprocating displacer or piston which has a thermal gradient from one end to the other suffers a loss of refrigeration due to heat transfer between the displacer/piston and the cylinder (shuttle heat transfer). This loss can be eliminated by designing an annular thermal regenerator on the outside diameter of the displacer/piston in such a manner as to match the temperature profile of the displacer/piston and the cylinder wall throughout the cycle.
Galdieri, John Vincent Jr., "A thermal analysis of a cryogenic expander with a reciprocating dispacer/piston incorporating an annular regenerator on the displacer/piston outside diameter" (1973). Theses and Dissertations. 4114.