基于Lagrangian模型与Eulerian模型耦合的建筑物周边气体扩散模拟

Simulation of pollutant diffusion based on Lagrangian/Eulerian hybrid model around buildings

该文旨在建立一个适用于城市建筑物周边的基于Lagrangian模型与Eulerian模型耦合的气体扩散数值模型,同时具有Lagrangian模型与Eulerian模型各自的优点,提高预测精度。该文利用耦合模型对单个建筑物周边的气体扩散过程进行数值模拟,并将平均风速、湍流动能和平均浓度几个参量的结果与风洞实验数据进行对比分析。结果表明,耦合模型对于建筑物周边靠近扩散源和远离扩散源的区域均能给出较高精度的预测结果。最后,利用COST-732模型评价方法对Lagrangian模型、Eulerian模型和耦合扩散模型实施了评价,其中耦合模型的评价结果最好。

A hybrid atmospheric dispersion method coupled with Lagrangian particle model and Eulerian model is proposed,which can be used for numerical simulation in areas around urban buildings.This method merges the advantages of Lagrangian model and Eulerian model together,and gives a high accuracy of prediction.The developed hybrid model is applied to the numerical simulation of gas diffusion around an isolated building.The mean wind velocity,TKE（Turbulent Kinetic Energy） and mean concentration have been discussed and compared with the wind tunnel data.The simulation results show that the hybrid model can give a high accuracy both in the regions close to the source and distant from the source.Finally,we use the COST-732 model to evaluate the prediction results of Eulerian,Lagrangian and the proposed hybrid model,and it is shown that the hybrid model can give the best simulation results.