Over the past few decades, experimental studies have been conducted on the condensation heat transfer of vapor mixtures. However, the local heat transfer characteristics of vapor mixture affected by surface tension have not been fully investigated. The present work, for the first time, suggested the CFD simulation method for the Marangoni condensation of ethanol-vapor mixture and analyzed the calculated result with flow structure. A CFD study has been performed for the condensation heat transfer of steam–ethanol mixtures on a horizontal tube to elucidate the Marangoni condensation phenomenon and the consequent heat transfer mechanism, which are difficult to fully obtain experimentally. In the present study, the numerical predictions of condensation heat transfer using a liquid film model agree well with those of the experimental results. The CFD analysis of steam–ethanol mixture compares with pure steam to clearly show the influence of surface tension on the heat transfer. In particular, when a small amount of ethanol is added to pure steam, the condensation heat transfer is enhanced because the local liquid film thickness is changed because of the surface tension gradient on the gas–liquid interface, which is caused by a concentration difference.

在过去的几十年中，已经对蒸气混合物的冷凝传热进行了实验研究。但是，尚未充分研究受表面张力影响的蒸汽混合物的局部传热特性。本文首次提出了CFD模拟方法对乙醇-蒸气混合物的Marangoni缩合进行模拟，并用流动结构对计算结果进行了分析。已经进行了CFD研究，用于在水平管上进行蒸汽-乙醇混合物的冷凝传热，以阐明马兰戈尼的冷凝现象和由此产生的传热机理，而这在实验上是很难完全获得的。在本研究中，使用液膜模型进行冷凝传热的数值预测与实验结果吻合良好。蒸汽-乙醇混合物的CFD分析与纯蒸汽进行比较，可以清楚地表明表面张力对传热的影响。特别是，当在纯蒸汽中添加少量乙醇时，由于局部液膜的厚度由于气液界面上的表面张力梯度（由浓度差异引起）而改变，从而提高了冷凝传热。