粗面流路における熱伝達率と圧力損失の相関について

概要

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A theoretical study of a turbulent channel flow was conducted to investigate the relationship between the heattransfer enhancement and the drag increase over rough surfaces using the timespace averaged momentum and energy equations. The results confirmed that the efficiency of the heat transfer surface, (i.e., the ratio of the heat transfer increase to the drag increase) is in general less than unity when the molecular Prandtl number Pr of the working fluid is less than the turbulent Prandtl number Pr_t. When Pr is greater than Pr_t, on the other hand, it was shown that the efficiency can be greater than unity as long as the roughness height is within the transitional region. It is suggested that the breakdown of the Reynolds analogy being experimentally observed over the heated riblet surface seems to be due to the inhomogeneity of the heat flux over the riblet surface when the thermal boundary layer is not yet fully developed.
一般社団法人日本機械学会の論文
1999-07-25