振荡流边界层中颗粒受力的三维格子玻耳兹曼模拟

3D lattice Boltzmann simulation of forces on a fixed spherical particle in oscillatory boundary layer flow

应用格子玻耳兹曼方法对振荡流边界层中单个颗粒在近壁面处的受力进行了三维模拟,计算结果与已有数值模拟结果(雷诺数为300)和实验结果(雷诺数为2000)进行了比较,吻合均较好。计算结果表明,当雷诺数为300时,在振荡流做正反向运动时力系数的幅值变化过程相同,横向涡量的空间分布具有对称性。雷诺数为2000时,紊动增强使力系数在不同流动方向时的变化有所差异,而且横向涡量的分布呈现非对称性,这时颗粒受到横向力作用。

Three-dimensional lattice Boltzmann method was employed to simulate the forces exerted on a fixed spherical particle close to the bottom in oscillatory boundary layer flow.Simulated results agree well with both the numerical results （when the Reynolds number Re is equaled to 300） and the experimental results （when Re=2000） reported in the literatures.In condition that Re=300,the force coefficient values possess the same variation process for both forward and reverse flow.The spatial distribution of the span-wise vortices is symmetric.For Re=2000,due to the increase of turbulence intensity,there exist differences in the evolution of force coefficients during forward and reverse flow,and the span-wise vortices show asymmetry distribution while the span-wise force is exerted on the particle.