同沙丘堆积形态对近地面起沙量影响的模拟分析

Simulation Analysis on the Effect of Sand Dune Forming on Near Surface Sediment Concentration

考虑气固两相间动量交换、升力等,利用欧拉双流体模型,建立了一个三维气固两相流动数学模型,以研究不同的近地面形状对起沙量的影响。采用Fluent流体力学软件,进行数值计算。对四种不同近地面沙粒堆集形状进行了模拟计算,验证了本模型和计算方法的正确性。研究区域高20m、长200m、宽20m,近地面风速廓线采用对数式。结果表明,沙粒堆集高度对沙粒质量流量有显著影响;当堆集高度相差不大时,各个近地面几何要素对起沙量有影响。此外,湍流对不同类型近地面形状的起沙量和沙粒相云图影响存在明显不同,需要进一步分析原因。

A three-dimensional gas-solid two-phase flow mathematical model was established by using Eulerian two-fluid model to study the effects of different near-surface shapes on sediment yield. Fluent fluid mechanics software was used for numerical calculation. The shape of four different near - surface sand stacks is simulated and verified, and the correctness of the model and calculation method is verified. The study area is 20m high, 200m long and 20m wide, and the surface wind speed profile is logarithmic. The results show that the height of sand grains has a significant effect on the mass flow of sand grains. When the height of the stack is not large, the geometric elements of the near ground are affected by the sediment. In addition, the influence of turbulence on sediment load and sandy phase cloud image of different types of near-surface shape is obviously different, and further analysis is needed.