基于Lagrangian-Eulerian耦合的放射性物质大气扩散模型研究

Research on Atmospheric Diffusion Model of Radioactive Material Based on Lagrangian-Eulerian Hybrid Model

针对中尺度扩散下拉格朗日模型和欧拉模型在计算效率和准确度方面的矛盾,建立了适用于模拟核事故下放射性物质大气扩散的基于拉格朗日模型与欧拉模型耦合的预测模型,以国内某核电站为例进行了放射性物质扩散的虚拟算例模拟,对模型进行验证和分析。结果表明:拉格朗日-欧拉耦合模型可以较好地模拟放射性物质在大气中的扩散,不仅可以提升中尺度和大尺度下的计算效率,还可以有效减小欧拉模型初始条件所带来的系统误差。

In view of the contradiction between the efficiency and accuracy of Lagrangian model and Eulerian model under mesoscale diffusion,a numerical modeling of dispersion of radionuclides based on Lagrangian-Eulerian hybrid model under nuclear accidents is proposed.Taking a domestic nuclear power plant as an example,a virtual case simulation of the diffusion of radioactive materials was carried out to verify and analyze the model.The results show that the Lagrangian-Eulerian hybrid model can effectively reduce the systematic error caused by the initial conditions of Eulerian model as well as improve the computational efficiency in the mesoscale and large scale.