パルス管内における流体変位の可視化と計測

抄録

In this study gas displacement in a pulse tube is visualized with the use of a light porous ball. The ball was placed in a transparent pulse tube and its displacement recorded on a videotape. The diameter and weight of the ball were predetermined in order to maintain errors in measurement within 5%. This visualization method has following advantages: (1) Real pulsetube refrigerators, which have a sharp temperature gradient along the pulse tube, can be used for measurement; (2) long-term measurements are possible without the use of special means; and (3) the process doesn't require a great deal of skill. Disadvantages include: (1) It is inapplicable to basic pulse-tube refrigerators; and (2) the intricate flow stream out of the hot end of the tube is invisible. Experimental results verify that the ball displacement can approximatery visualize the gas displacement. An orifice pulse-tube refrigerator that utilizes air as the refrigerant was used for this experiment. Under the conditions of various valve-open angles, the gas displacement and phase shift in a double-inlet pulse-tube refrigerator were measured.