LAUSR

This study compares detailed regime maps in the case of operation using the air of two Ranque tubes with circular and square working channels with identical inlet guides and identical outlets. The degree of air expansion and the fraction of a flow rate through a cold outlet vary in ranges of 2–8 and 0.2–0.8, respectively. It is observed for both tubes that, as the degree of expansion increases, the dependences of a volumetric flow rate and a cooling ratio on the fraction of a cold flow rate become invariant. It is revealed that the cooling ratio in a circular tube is 1.5–2.0 times greater than that in a square channel, with the volumetric flow rate therein being approximately 10% lower.