Numerical Simulation Research On Water Fog Diffusion From Flood Discharge Energy Dissipation Based On WRF/CALPUFF

Water fog is a form of flood discharge atomization,and its diffusion result is directly related to the spatial distribution of water fog,and is closely related to the temperature and humidity of the environment.In this paper,based on WRF numerical model,CALMET diagnostic wind field model and CALPUFF unsteady three-dimensional Lagrangian model we conducted an in-depth study on the flood fog diffusion of hydropower station.The main research contents are as follows:(1)Establish WRF/CALPUFF flood discharge fog diffusion model.According to the different generation mechanism of the fog source,the fog source diffused by the flood discharge fog is generalized to a horizontal line source,and the differential equation system of the movement of the water tongue and water tongue is proposed,and different energy dissipation methods are given.The theoretical calculation method of the position of the line source and the amount of fog source.Based on the WRF numerical weather forecast model and the Newton relaxation assimilation method,the CALMET diagnostic wind field model was introduced,the resolution of the numerical simulation was increased to 20m,and the CALPUFF unsteady three-dimensional Lagrangian model was introduced to achieve the assimilation Under the conditions of meteorological factors affecting flood discharge,the numerical simulation of the water fog diffusion process.The reliability of the WRF/CALPUFF flood discharge fog diffusion model was verified by the verification calculation of the bottom discharge flooding atomization of the Wantang Hydropower Station and the evaluation of the calculation results using the Nash coefficient.(2)Study on the effect of fog source characteristics on the diffusion of underflow discharge flood fog.Aiming at the source intensity and fog source particle size,the WRF/CALPUFF flood discharge fog diffusion model was used to study the influence of fog source characteristics on the spread range and rainfall intensity of the Xiangjiaba bottom flood discharge fog.Quantitative analysis of the calculation results shows that the source intensity increases,the water fog diffusion and rainfall range increases,and the water fog concentration and rainfall intensity also increase;the particle size increases,the water fog diffusion range decreases,and the concentration also The smaller the rainfall range,the greater the rainfall intensity.Compared with the drop spectrum,the source intensity has a more significant effect on the flood fog spread range and rainfall intensity.(3)Numerical simulation study of flood fog diffusion in Ertan flooding.The WRF/CALPUFF flood discharge fog diffusion model was used to numerically calculate the three working conditions of Ertan surface hole energy dissipation,middle hole energy dissipation and surface hole energy dissipation in the table,and compare the simulation results with the prototype observation data To verify the reliability of the model.By comparing the three working conditions,the effects of different flood discharge energy dissipation schemes on the spread of water fog are analyzed.The study found that the combined flood discharge scheme of the surface and middle holes greatly increases the range of water fog diffusion compared to the individual flood discharge schemes of the surface and middle holes.