一个对流边界层中的随机扩散模式

通过对对流边界层(CBL)湍流结构的分析,首次提出用两种不同尺度的湍流模拟CBL中的铅直扩散.在此基础上发展了一个随机扩散模式,并用它模拟了典型对流条件下两种高架连续点源的扩散.与Willis水槽模拟和Lamb等人数值模拟以及CONDORS计划外场试验的结果的比较表明,本模式能成功地模拟CBL中的横向积分浓度.与其它数值模式相比,还具有输入参数少、计算量极小和更加简单实用的优点.

A random walk diffusion model in the convective boundary layer

After analysing the structure of turbulence in convective boundary layer (CBL), it is first suggested that the vertical diffusion in CBL can be simulated by turbulence on two different scales, and then a simple random walk diffusion model for CBL is developed. Two cases of elevated continuous point sources in a typical convective condition are simulated in comparison with the Willis and Deardorff water tank modelling, Lamb's numerical simulation, and CONDORS field experiments. We are confident that the model can successfully simulate the cross-wind integrated concentration distribution in CBL, and that our model has advantages of using less input parameters, much short computation time and is more suitable for practical uses.