论文标题
rans and Les之间的界面上的晶格玻尔兹曼方法的合成湍流发生器
Synthetic turbulence generator for lattice Boltzmann method at the interface between RANS and LES
论文作者
论文摘要
该论文在雷诺平均的Naiver-Stokes方程（RANS）方程和LBM大型涡流模拟（LES）的界面上介绍了晶格玻尔兹曼方法（LBM）的合成湍流发生器（STG）。我们首先从界面处的有限体积求解器获取速度场。然后，由于RANS和LBM的不同网格类型，我们将数值插值从RANS速度场插入到LBM速度场。 STG方法会生成速度波动，并且正则化LBM重建粒子分布在界面处的功能。我们在RE_τ= 180处执行湍流通道流量模拟，在入口处的STG和出口处的无压边界条件。与周期性晶格玻尔兹曼（LES-LBM）通道流量和直接数值模拟（DNS）通道流量相比，速度场进行定量比较。评估了STG方法的适应长度和时间。此外，我们将STG-LBM通道流量结果与现有的LBM合成EDDIES方法（SEM-LBM）结果进行了比较。我们的数值研究表明，与DNS和周期性LES-LBM通道流相吻合良好。定量分析湍流通道流的适应时间，并匹配DNS约1.5至3个域流动时间。最后，我们检查了流向方向的不同横截面的速度组件的自动相关。拟议的STG-LBM既快速又健壮。这些发现在空气动力学模拟和广泛的工程应用方面的混合RANS/LES-LBM求解器显示出良好的潜力。
The paper presents a synthetic turbulence generator (STG) for the lattice Boltzmann method (LBM) at the interface of the Reynolds averaged Naiver-Stokes (RANS) equations and the LBM Large Eddy Simulation (LES). We first obtain the RANS velocity field from a finite volume solver at the interface. Then, we apply a numerical interpolation from the RANS velocity field to the LBM velocity field due to the different grid types of RANS and LBM. The STG method generates the velocity fluctuations, and the regularized LBM reconstructs the particle distribution functions at the interface. We perform a turbulent channel flow simulation at Re_τ = 180 with the STG at the inlet and the pressure-free boundary condition at the outlet. The velocity field is quantitatively compared with the periodic lattice Boltzmann based LES (LES-LBM) channel flow and the direct numerical simulation (DNS) channel flow. Both adaptation length and time for the STG method are evaluated. Also, we compare the STG-LBM channel flow results with the existing LBM synthetic eddies method (SEM-LBM) results. Our numerical investigations show good agreement with the DNS and periodic LES-LBM channel flow within a short adaptation length. The adaptation time for the turbulent channel flow is quantitatively analyzed and matches the DNS around 1.5 to 3 domain flow-through time. Finally, we check the auto-correlation for the velocity components at different cross-sections of the streamwise direction. The proposed STG-LBM is observed to be both fast and robust. The findings show good potential for the hybrid RANS/LES-LBM based solver on the aerodynamics simulations and a broad spectrum of engineering applications.
