The dissolution of minute concentration of polymers in wall-bounded flows is well-known for its unparalleled ability to reduce turbulent friction drag. Another phenomenon, elasto-inertial turbulence (EIT), has been far less studied even though elastic instabilities have already been observed in dilute polymer solutions before the discovery of polymer drag reduction. EIT is a chaotic state driven by polymer dynamics that is observed across many orders of magnitude in Reynolds number. It involves energy transfer from small elastic scales to large flow scales. The investigation of the mechanisms of EIT offers the possibility to better understand other complex phenomena such as elastic turbulence and maximum drag reduction. In this review, we survey recent research efforts that are advancing the understanding of the dynamics of EIT. We highlight the fundamental differences between EIT and Newtonian/inertial turbulence from the perspective of experiments, numerical simulations, instabilities, and coherent structures. Finally, we discuss the possible links between EIT and elastic turbulence and polymer drag reduction, as well as the remaining challenges in unraveling the self-sustaining mechanism of EIT.

中文翻译：

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弹惯性湍流


壁限流中微量聚合物的溶解因其无与伦比的减少湍流摩擦阻力的能力而闻名。尽管在发现聚合物减阻之前已经在稀聚合物溶液中观察到弹性不稳定性，但另一种现象，即弹性惯性湍流（EIT）的研究却少得多。 EIT 是一种由聚合物动力学驱动的混沌状态，可以在雷诺数的多个数量级上观察到。它涉及从小弹性尺度到大流动尺度的能量传递。 EIT 机制的研究为更好地理解其他复杂现象（例如弹性湍流和最大减阻）提供了可能性。在这篇综述中，我们调查了最近正在推进对 EIT 动态的理解的研究工作。我们从实验、数值模拟、不稳定性和相干结构的角度强调了 EIT 和牛顿/惯性湍流之间的根本区别。最后，我们讨论了 EIT 与弹性湍流和聚合物减阻之间可能的联系，以及阐明 EIT 自我维持机制中仍然存在的挑战。