标题： 速度场中浮力驱动湍流引起的羽流各向异性解耦 显示英文标题

标题： Disentangle plume-induced anisotropy in the velocity field in buoyancy-driven turbulence

摘要： 我们提出一种方法，用于解耦湍流速度场中由悬崖结构产生的各向异性，并在湍流瑞利-贝纳德（RB）对流系统中进行测试。 发现RB系统中速度场中的悬崖结构是由热射流产生的。 这些悬崖结构导致速度增量的不对称性，使我们考虑正和负的速度结构函数（VSF）。 正的速度增量排除了悬崖结构，而负的则包含它们。 我们的结果表明，正的VSF的标度指数与均匀各向同性湍流（HIT）预测的结果非常一致，而负的VSF在热射流丰富的区域显示出与HIT预期显著偏离。 这些结果表明，正和负的VSF可用于定量研究速度场中悬崖结构的影响，并有效解耦由这些结构引起的各向异性。 显示英文摘要

摘要： We present a method of disentangling the anisotropies produced by the cliff structures in turbulent velocity field and test it in the system of turbulent Rayleigh-B\'{e}nard (RB) convection. It is found that in the RB system the cliff structures in the velocity field are generated by thermal plumes. These cliff structures induce asymmetry in the velocity increments, which leads us to consider the plus and minus velocity structure functions (VSF). The plus velocity increments exclude cliff structures, while the minus ones include them. Our results show that the scaling exponents of the plus VSFs are in excellent agreement with those predicted for homogeneous and isotropic turbulence (HIT), whereas those of the minus VSFs exhibit significant deviations from HIT expectations in places where thermal plumes abound. These results demonstrate that plus and minus VSFs can be used to quantitatively study the effect of cliff structures in the velocity field and to effectively disentangle the associated anisotropies caused by these structures.