论文标题
在低马赫数处的Anisothermal湍流通道流中的亚网格尺度模型的先验测试
A priori tests of subgrid-scale models in an anisothermal turbulent channel flow at low mach number
论文作者
论文摘要
使用直接数值模拟研究了低马赫数的亚网格规模建模。该研究基于低马赫数方程的过滤，该方程适用于具有高度可变流体特性的低马赫数流。结果与经典过滤器或Favre滤波器建立的过滤的低马赫数方程的公式有关。考虑了过滤后的低马赫数方程的两个最重要的子网格术语。它们与动量对流和密度 - 速度相关性有关。我们专注于涡流和涡流模型。分析了文献中的亚网格规模模型，并提出了两个新模型。使用强烈动脉热完全开发的湍流流量的直接数值模拟的瞬时流场将亚网格尺度模型与精确的子网格项进行比较。在模型性能方面，使用经典和favre过滤器之间没有显着差异。我们建议这些模型应考虑到滤波器长度的渐近近壁行为。涡流粘度和涡流模型能够代表子网格术语的能量贡献，而不是其在流程中的效果。与先验测试中的其他研究模型相比，发现AMD和标量AMD模型与确切的子网格术语的吻合更好。
The subgrid-scale modelling of a low Mach number strongly anisothermal turbulent flow is investigated using direct numerical simulations. The study is based on the filtering of the low Mach number equations, suited to low Mach number flows with highly variable fluid properties. The results are relevant to formulations of the filtered low Mach number equations established with the classical filter or the Favre filter. The two most significant subgrid terms of the filtered low Mach number equations are considered. They are associated with the momentum convection and the density-velocity correlation. We focus on eddy-viscosity and eddy-diffusivity models. Subgrid-scale models from the literature are analysed and two new models are proposed. The subgrid-scale models are compared to the exact subgrid term using the instantaneous flow field of the direct numerical simulation of a strongly anisothermal fully developed turbulent channel flow. There is no significant differences between the use of the classical and Favre filter regarding the performance of the models. We suggest that the models should take into account the asymptotic near-wall behaviour of the filter length. Eddy-viscosity and eddy-diffusivity models are able to represent the energetic contribution of the subgrid term but not its effect in the flow governing equations. The AMD and scalar AMD models are found to be in better agreement with the exact subgrid terms than the other investigated models in the a priori tests.
