School of Physics, Georgia Institute of Technology, Atlanta, GA 30332.
Proc Natl Acad Sci U S A. 2022 Aug 23;119(34):e2120665119. doi: 10.1073/pnas.2120665119. Epub 2022 Aug 19.
Despite a long and rich history of scientific investigation, fluid turbulence remains one of the most challenging problems in science and engineering. One of the key outstanding questions concerns the role of coherent structures that describe frequently observed patterns embedded in turbulence. It has been suggested, but not proved, that coherent structures correspond to unstable, recurrent solutions of the governing equation of fluid dynamics. Here, we present experimental and numerical evidence that three-dimensional turbulent flow tracks, episodically but repeatedly, the spatial and temporal structure of multiple such solutions. Our results provide compelling evidence that coherent structures, grounded in the governing equations, can be harnessed to predict how turbulent flows evolve.
尽管科学研究已经有很长的历史和丰富的经验，但流体湍流仍然是科学和工程领域最具挑战性的问题之一。其中一个关键的未解决问题涉及到相干结构的作用，相干结构描述了经常在湍流中观察到的模式。虽然有人提出，但尚未证明，相干结构对应于流体动力学控制方程的不稳定、反复出现的解。在这里，我们通过实验和数值证据表明，三维湍流流迹会间歇性但反复地跟踪多个这样的解的时空结构。我们的结果提供了令人信服的证据，表明基于控制方程的相干结构可以被用来预测湍流的演化。
