风沙跃移轨迹的DPM数值模拟

Sand Saltation Trajectory of DPM Numerical Simulation

对风沙跃移运动采用离散模型进行数值计算,对沙粒相采用离散相模型(DPM模型),研究沙粒在跃移运动过程中的运动轨迹与摩阻风速及粒径大小的关系。模拟结果表明:随摩阻风速的增大,跃移轨迹高度逐渐降低,跃移轨迹长度逐渐增长;随沙粒粒径的增大,跃移轨迹高度逐渐增大,跃移轨迹长度逐渐缩短;跃移轨迹长度与跃移轨迹高度的比值(L/H)随摩阻风速的增大而增大,呈对数关系,随沙粒粒径的增大而减小,呈幂函数关系。

The wind- blown sand movement is numerically simulated based on DPM model. The relationships between trajectories of saltating sands and friction velocities and sand diameters are analyzed based on the simulation results. The results show that the height of trajectories reduce gradually with the increase of friction wind speed and increase with the increase of particle size;instead, the length of trajectories increase with the increase of friction wind speed and decrease with the increase of particle size. The ratio of trajectories' length and their height (L/H) increase with the increase of wind speed, presenting to be a logarithmic relationship;and decrease with increasing of sand particle size, appearing to be power function relationship.