Considering the current advances in experimental capabilities in fluid mechanics and the advances in computing power and numerical methods in computational fluid mechanics, a question that naturally arises is whether the two sets of techniques are approaching a level of sophistication sufficiently high to deliver results on turbulent flows in realistic geometries that are comparable. The purpose of this paper is to give elements of answers to this question by considering the so-called von Karman flow where the fluid in a cylindrical container is driven by two counter-rotating impellers. We compare in the mentioned flow the torque and the flow topology obtained by experiments, direct numerical simulations (DNS), and large eddy simulations (LES) at various Reynolds numbers ranging from R e = O(10 2) to R e = O(10 5). In addition to validating the proposed LES model, the level of agreement that is observed between the numerical and the experimental data shows that the degree of accuracy of each of these techniques is reaching a threshold beyond which it is possible to use each of them with high confidence to explore and better understand turbulence in complex flows at R e = O(10 5) and beyond.

中文翻译：

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具有移动边界的现实几何中的湍流：当模拟遇到实验时

考虑到当前流体力学实验能力的进步以及计算流体力学计算能力和数值方法的进步，自然会产生一个问题，即这两组技术是否接近足够高的复杂程度以提供湍流结果在具有可比性的现实几何中。本文的目的是通过考虑所谓的 von Karman 流来回答这个问题，其中圆柱形容器中的流体由两个反向旋转的叶轮驱动。我们在上述流动中比较了通过实验、直接数值模拟 (DNS) 和大涡模拟 (LES) 在不同雷诺数范围内从 Re = O(10 2) 到 Re = O( 10 5)。