A Comparative Study Of Air Pollutant Diffusion Models Dased On OpenFOAM

With the continuous development of my country's urbanization and industrialization process,the air pollutants emitted during the construction and development process will affect the health of the surrounding people and the safety of property.Analyzing the diffusion law of atmospheric pollutants through computer simulation technology provides a scientific basis for people to understand the process of pollutant discharge and concentration distribution.The accuracy of the atmospheric diffusion model is crucial to the calculation of atmospheric diffusion flow.Therefore,conducting research on the atmospheric diffusion model of pollutants is the key to ensuring residents' health,property safety and ecological protection.However,there are few comparative studies on atmospheric diffusion models of atmospheric pollutants in nuclear power plants.Therefore,this paper compares and analyzes the two atmospheric diffusion models(CFD turbulence model and Gaussian plume diffusion model)for the above-mentioned problems with Fuqing Nuclear Power Plant as the research object,so as to obtain a suitable atmospheric diffusion model.The specific research content of this article is as follows:(1)First select the classical wind tunnel experimental data to compare the five turbulence models(standard k-? model,Realizable k-? model,RNG k-? model,standard)in the two CFD(Computational Fluid Dynamics)software(OpenFOAM,Fluent)k-? model,SST k-? model)for numerical simulation verification and analysis,it is concluded that the calculation results of the Realizable k-? turbulence model in OpenFOAM software are the closest to the wind tunnel test results,and the simulation accuracy is the highest.(2)The five turbulence models in the OpenFOAM software were used to calculate the Fuqing Nuclear Power Plant area,and the five turbulence models were found to be consistent in the flow field above the building.The main difference occurred near the building wall and the wake area of the building.And in the area of different adjacent buildings.At the same time,through the analysis of wind speed u,turbulent kinetic energy k and dissipation rate ? under the five turbulence model buildings,it is concluded that the Realizable k-? turbulence model is also suitable for the factory model with more ground buildings.Finally,on the basis of the calculation results of the wind field,the concentration diffusion equation is added,and the mysimple Foam solver is compiled to solve it,and the concentration distribution law of the air pollutants in the nuclear power plant is obtained.(3)Calculate the air pollutant diffusion results in Matlab based on the Gaussian plume model,and compare this result with the results of the CFD turbulence diffusion model.It is concluded that when the Gaussian plume model is not blocked by buildings,the results are the same as the CFD values.The simulation results are basically the same,but the situation of pollutant diffusion cannot be well simulated when there are buildings sheltered.Therefore,the CFD turbulence diffusion model is more suitable for the study of the atmospheric pollutant diffusion process in the plant area under actual conditions.