粗糙床面振荡紊流边界层运动的三维格子玻尔兹曼模拟

该文采用格子玻尔兹曼(LB)方法建立了紧密排列颗粒粗糙床面振荡紊流边界层模拟的三维数学模型。收集粗糙床面波浪水槽实验结果,对水槽实验条件下的振荡流边界层进行模拟,模拟得到的平均流速、紊动特性、等效粗糙高度、摩阻系数和边界层厚度等与实验结果进行了全面对比,并对三维涡旋结构进行了分析。结果表明,所建立的LB数学模型可以合理模拟粗糙床面振荡流边界层流动,能够反映三维涡旋特性,可进一步应用于粗糙床面振荡流紊动特性以及床面粗糙参数的研究。

3-D lattice Boltzmann simulation of turbulent oscillatory boundary layer flow over rough beds

A 3-D numerical model based on lattice Boltzmann (LB) method is established to simulate the oscillatory boundary layer flow over rough beds of packed spheres.The simulation conditions are set up according to a wave flume experiment.The simulation results,including the averaged velocity,turbulent characteristics,equivalent roughness height,friction factor and boundary layer thickness,are presented and compared to experimental measurements.The 3-D vortex structures are analyzed as well.The comparisons confirm the capability of the 3-D LB model for appropriately representing the characteristics of oscillatory boundary layer flow over rough beds.The analysis of the examined case shows that the LB model can be used in further studies.