Abstract
The working gas flow in a rectangular pulse tube refrigerator was visualized using the Schlieren technique in order to understand characteristics of a gas piston. The experiments were conducted with inertance tube lengths of 700mm, 1350mm, 2100mm. One side of the gas piston end that was the boundary of a jet from a regenerator was observed. The lowest cool-down temperature was -19℃ at the condition of the inertance tube length 1350mm. At this condition, it was found that the gas piston end was just reached at the regenerator when the direction of a compression piston was changed from expansion to compression.
