基于OpenFOAM的核电厂气态污染物扩散数值模拟研究OA

A computational method for maintaining the inlet velocity and turbulent kinetic energy profiles downstream of the computational domain under neutral stratification was implemented based on OpenFOAM.This method adopted the logarithmic law velocity and turbulent kinetic energy inlet profiles,combined with the standard k-ε turbulence model with modified model coefficients,and the modified wall function incorporating roughness height.Based on this method,the velocity distribution and cavity zone length basically consistent with the experimental results were obtained in the flow around a single cubic building,verifying the effectiveness of the method.Taking the complex underlying surface composed of a nuclear power plant and its surrounding terrain as an example,a numerical simulation study on gaseous pollutant diffusion under neutral stratification was carried out,and the simulation results were verified and analyzed using wind tunnel experiment data.The results showed that the velocity,turbulence intensity,and pollutant dispersion factor varying with height at different positions obtained by CFD simulation were basically consistent with the wind tunnel experiment results.The dispersion factor errors at 1 000 and 1 500 m downstream of the pollution source met the FAC2 criterion.The effectiveness of the adopted numerical simulation method was verified,providing a new approach for the study of pollutant diffusion over complex underlying surfaces of nuclear power plants.