多孔涂层对超流氦换热的传热强化作用

HEAT TRANSFER ENHANCEMENT IN SUPERFLUID HELIUM BY MEANS OF POROUS COATINGS

采用简单的对试件涂多孔层的手段，强化团体与起流氦之间的换热．利用超流氦的热力效应使试件多孔层内部的超流氦建立起压力增量，使液氦过冷，从而获得加压（过冷）超流氦的传热性能，选择了医用多孔细菌过滤片、石膏粉以及石膏矾土混合物为多孔材料，在ＲｈＦｅ和Ｃｕ丝上进行了传热实验，强化效果十分明显．

Coating wire using porous materials with appropriate pore size is a simple way to enhance heat transfer between solid and superfluid helium. The thermo-mechanical effect of superfluid is utilized to set up a pressure increase of liquid helium in porous layer, therefore theliquid becomes subcooled and exerts a good influence on heat transfer with the outstandingperformance of He Ⅱ p. different porous materials (capillary filter, gypsum and gypsum-alumina mixture ) are used as coatings of RhFe and Cu wires. Successful heat transfer measurements were done in He I s(1. 6 K to 2. 1 K)' The results show a strong improvement compared with those of bare wire.