The nonlinear large-eddy simulation method applied to Sc≈1 and Sc⪢1 passive-scalar mixing
The nonlinear large-eddy simulation method applied to Sc≈1 and Sc⪢1 passive-scalar mixing
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应用于Sc≈1和Sc⪢1被动标量混合的非线性大涡模拟方法
DOI：
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发表时间：
2008
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通讯作者：
G. Burton
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作者：
G. Burton
非线性大涡模拟 (nLES) 方法在此扩展到模拟被动标量场的 Sc≈1 和 Sc⪢1 湍流混合。这些是第一个在高施密特数状态下在粘性对流尺度上重现标量能量场 ψ2(x,t) 瞬时结构的 LES 研究。该模拟采用了由 G. C. Burton 和 W. J. A. Dahm 首先提出的多重分形建模的 nLES 方法的改进 [Phys.流体 17, 075111 (2005)]。在这种方法中，使用亚网格速度和标量场 ujsgs 和 phisgs 的多重分形模型，直接计算滤波纳维-斯托克斯方程中的非线性惯性应力 uiuj´ 和滤波平流扩散方程中的非线性标量通量 ujφ´ 。解析的能量水平由新的自适应反向散射限制器控制，该限制器可根据变化的流动条件进行局部调整，与实际流体动力湍流中控制能量传递的机制一致。无人工粘度或扩散...
The nonlinear large-eddy simulation (nLES) method is extended here to simulations of Sc≈1 and Sc⪢1 turbulent mixing of passive-scalar fields. These are the first LES studies to reproduce the instantaneous structure of the scalar-energy field ϕ¯2(x,t) at viscous-convective scales in the high Schmidt-number regime. The simulations employ a refinement of the nLES method with multifractal modeling first proposed by G. C. Burton and W. J. A. Dahm [Phys. Fluids 17, 075111 (2005)]. In this approach, the nonlinear inertial stresses uiuj¯ in the filtered Navier–Stokes equation and the nonlinear scalar fluxes ujϕ¯ in the filtered advection-diffusion equation are calculated directly, using multifractal models for the subgrid velocity and scalar fields, ujsgs and ϕsgs. Resolved energy levels are controlled by a new adaptive backscatter limiter that adjusts locally to changing flow conditions consistent with the mechanism governing energy transfer in actual hydrodynamic turbulence. No artificial viscosity or diffusivi...