Abstract Surfactant drag reduction has wide applications in energy power and chemical industries. However, the drag reduction ability will be weakened or lost during long-term applications. We studied the surfactant drag reduction in turbulent pipe flow using coarse-grained molecular dynamics simulations and cryogenic transmission electron microscopy experiments. The results show that the weakening/loss of surfactant drag reduction ability occurs under the following conditions: weak alkalinity of the solution, tiny rust particles in the solution, and/or the rusty wall of the pipeline. Weak alkalinity conduces to irregular structures of surfactant micelles, charged tiny iron rust particles can adsorb the surfactant micelles and fill into micelle network gaps, and the rusty wall could adsorb part of the surfactant micelles and lessen the global micelle network structure. All the three can destroy the micelle network structure and result in partial or complete failure of the turbulent drag reduction.

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表面活性剂减阻能力减弱或丧失：粗粒分子动力学研究

摘要 表面活性剂减阻剂在能源、化工等行业有着广泛的应用。但是，在长期应用过程中，减阻能力会减弱或丧失。我们使用粗粒分子动力学模拟和低温透射电子显微镜实验研究了湍流管道中的表面活性剂减阻。结果表明，表面活性剂减阻能力的减弱/丧失发生在以下条件下：溶液弱碱性、溶液中存在微小的铁锈颗粒和/或管道壁生锈。弱碱性导致表面活性剂胶束结构不规则，带电的微小铁锈颗粒可以吸附表面活性剂胶束并填充胶束网络间隙，锈壁会吸附部分表面活性剂胶束，减少整体胶束网络结构。这三者都会破坏胶束网络结构，导致湍流减阻部分或完全失效。