Numerical simulation and experimental investigation of a novel Scotch yoke for a Gifford-McMahon cryocooler

[摘要] A novel Gifford-McMahon (GM)cycle,called anasymmetric GM cycle,is proposed. In an asymmetric GM cycle, the displacer moves slowly when it is adjacentto the upper dead pointbut moves rapidly when it is adjacentto the lower dead point. Therefore, the expansion process is longer, while the discharging process is shorter than in a conventional GM cycle. Meanwhile, the duration of the charging process can be kept the same as that in a conventional GM cycle. Accordingly, the phase shiftbetween the pressure and the displacement can be improved, and the mass flow rate into the expansion space can also be increased. Therefore, the P-V work and the cooling capacity can be increased. To implementthe GM cycle, a novel Scotch yokewas invented. In the Scotch yoke, there is a concave part at the upper center of the slide groove and a convex part at the lower center of the slide groove. The effect of the Scotch yoke has been confirmed by numerical simulation and experimental investigation. With a conventional Scotch yoke, the cooling capacity was 44 W at 37.4 K at the first stage and 1.0 W at 3.94 K at the second stage. With a novel Scotch yoke, the cooling capacity was 44 W at 35.9 K at the first stage and 1.0 W at 3.96 K at the second stage. The cooling capacity at the first stage at 40 K was improved by about 10%, from 51.5 W to 57.3 W.

[发布机构] Technology Research Center, Sumitomo Heavy Industries, Ltd., 2-1-1, Yato-cho, Nishitokyo, Tokyo; 188-8585, Japan^1

[效力级别] 物理学 [学科分类] 材料科学（综合）

[关键词] Charging process;Convex parts;Cooling Capacity;Discharging process;Expansion process;Expansion space;Experimental investigations;Mass flow rate