陕西关中增雨播云线源输送扩散数值模拟

Numerical simulation of transport and diffusion of seeding line source in Guanzhong Region

利用层状云播云线源输送扩散三维时变烟团轨迹模式 ,通过对陕西关中飞机增雨作业实例的数值模拟研究 ,结果表明 :模拟的播云线源输送扩散特征与输送扩散的基本理论和一般规律相吻合 ,并且再现了非垂直 (与风向 )多条播云线源非均匀非定常的输送扩散特点 ;浓度等值线的水平分布和垂直分布均不规则 ,比均匀定常点源更为复杂 ,整体不满足高斯浓度分布 ,表明在这种情况下均匀定常模式已不适用。另外 ,模式能够精确地模拟出播云线间的精细结构。播云线源水平输送距离 1 h平均为 65 km,扩散速率 1 h平均为 0 .82

A formulated three dimensional time variable puff model is used to stimulate an operation of rain enhancement.The model results show that the simulated diffusive features of multiple line sources not only are consistent with basic theory of diffusion, but also reproduce their characteristics of heterogeneity and unsteadiness non vertical to wind direction. The horizontal and vertical concentration distributions are irregular, and more complex and variable with space and time, compared to diffusion of vertical line source under homogeneous and steady point source. Besides, the model can simulate the subtle and detailed structure of each line source. For the seeding line sources, the average horizontal transport distance reaches 65 km after 1 hour, and the diffusion rate is 0.82ms -1 for average of one hour.