Experimental research of high frequency tapered pulse tube cooler

Tapered pulse tube, corresponding to traditional cylinder tube, is a special design of pulse tube coolers. In this paper, different types of tapered pulse tube arrangements with different angles are tested based on our optimized high frequency PTC. Experiments show that PTCs with tapered PTCs, either to hot or cold end, degrade the performance of PTC in comparison to the cylinder tube. This paper proposes and tests for the first time CD tapered pulse tube. This special tapered pulse tube from two directions, with big diameter at two ends and small diameter in the middle, is similar to converging–diverging nozzle. It improves the performance of PTC over the optimized cylinder tube, though the improvement is only about 1–2 K in minimum temperature.