Title: Fluctuation-induced forces in homogeneous isotropic turbulence Show Chinese title

Title: 均匀各向同性湍流中的涨落诱导力

Abstract: Understanding force generation in non-equilibrium systems is a significant challenge in statistical physics. We uncover a surprising fluctuation-induced force between two plates immersed in homogeneous isotropic turbulence using Direct Numerical Simulation. The force is a non-monotonic function of plate separation. The mechanism of force generation reveals an intriguing analogy with fluctuation-induced forces: energy in the fluid is localised in regions of high vorticity, or "worms", which have a characteristic length scale. The magnitude of the force depends on the packing of worms inside the plates, with the maximal force attained when the plate separation is comparable to the characteristic worm length. A key implication of our study is that the length scale-dependent partition of energy in an active or non-equilibrium system determines force generation. Show Chinese abstract

Abstract: 理解非平衡系统中的力生成是统计物理中的一个重大挑战。 我们通过直接数值模拟揭示了在均匀各向同性湍流中浸没的两块板之间存在一种令人惊讶的波动诱导力。 这种力是板间距的非单调函数。 力生成的机制揭示了与波动诱导力的有趣类比：流体中的能量集中在高涡度区域，或“虫”状结构中，这些结构具有特征长度尺度。 力的大小取决于板内“虫”的排列密度，当板间距与特征“虫”长度相当时，力达到最大值。 我们研究的一个关键含义是，在活性或非平衡系统中，与长度尺度相关的能量分配决定了力的生成。