中文摘要：

对弯段温差剪切分层流的断面环流微细结构与掺混强度特征进行了试验研究。选取45°、90°、180°三种不同弯曲度水槽，探求了密度分层流从明显分层到强混合状态下断面环流结构的演变过程，发现了明显分层与强混合两种不同状态下3个环流结构的区别，捕捉到了从分层态向混合态转捩过程中临界情况下四环流结构存在的现象，揭示了明显分层与强混合状态不同断面环流结构的根本机理；同时也对不同弯曲强度情况下掺混强度的沿程变化规律进行探讨与研究。

英文摘要：

The microstructure of circumfluence and the characteristic of the mixing intensity on the cross-section of thermally stratified shear flow in curved flumes are studied experimentally. By the experimental investigation of the curved flumes with three different sinuosities of 45°, 90° and 180°, the transition of the circumfluent structure on the cross-section from the stable stratification to mixing is explored. The four-circulation patterns of the secondary flow are first detected at the critical condition of the conversion of the stable stratification to mixing. Moreover, the differences of three-circulation patterns of the secondary flow between stable stratification and mixing are also first discovered, and the reasons of difference between two situations are investigated. In addition, the change process of the mixing intensity along the curved flumes is obtained.