Research On Cloud Toxic Gas Diffusion In Urban Community Simulation

The simulation of gas diffusion can provide powerful support for military,state security and safe production supervision departments,such as emergency rescues,crisis precautions,subject maneuvers and so on.However,the traditional pollutants diffusion model is unable to effectively simulate gas diffusion in urban community,and the poor computational precision cannot be used as a reference.What's more,the computational fluid dynamics software which is frequently-used requires higher operability and its computing efficiency cannot provide the support for emergency rescues.Cloud computing provides a new method for gas diffusion simulation in urban community due to its powerful computing capacity and the convenience of cloud workflow.Therefore,this study takes the example of the Yishan Campus of Fuzhou University to study,carries out the research on three-dimensional modeling for the underlying surface of diffusion field,computational grid constructing,numerical model constructing for gas diffusion and service encapsilating,workflow compositing based on cloud computing in the background of the emergency rescue of gas leakage&diffusion accidents in urban community,we also build on-line services of numerical simulation network for gas diffusion in Urban Community.In addition,the gas diffusion simulation service is published on GeoKSCloud,critical technical supports and system decision-making services can be provided for gas diffusion accidents in urban community.Primary researches are included as follows:1.Focusing on 3D model construction for the diffusion field,diffusion space grid partitioning,numerical model generation for computational fluid dynamics,etc.,urban community gas diffusion simulation system is designed with the urban community gas leakage&diffusion accident being typical background.After a brief introduction to the system's application background and demand analysis,our system construction task is determined.Meanwhile,the overall framework and module functions of this system as well as specific grid enablement services and numerical computation atomic services,etc.are all designed in detail.2.Based on the design of urban community gas diffusion simulation system,a cloud service system for urban community gas diffusion simulation is implemented on GeoKSCloud platform.By taking the gas diffusion simulation of Yishan Campus Demonstration Area of Fuzhou University as a specific example,3D space environment construction and mesh generation,etc.are performed directing at buildings and terrains.Decomposition,programming realization and deployment on the GeoKSCloud platform of the numerical calculation process are conducted in accordance with such a process of computational fluid dynamics.In the end,service composition modeling for numerical calculation atomic services generated on the basis of PISO algorithm is performed onaccount of workflow so as to obtain an intact urban community gas diffusion simulation service.3.The urban community gas diffusion simulation composition service is adopted to simulate gas diffusions in Yishan Campus Demonstration Area of Fuzhou University.Diffusion zone is divided according to a principle of chlorine of different concentrations doing harms in different degrees to human health.In addition,simulation results of urban community gas diffusion simulation cloud service are analyzed compared with those of traditional pollutant dispersion simulation and Fluent which is computational fluid dynamics software for commercial use.Comparison results indicate that the former results are comparatively rational and more accurate,and they are basically consistent with those of Fluent in spite of some slight differences in details.For all monitoring points,the average deviation is 6.96%.At each monitoring point,the maximum deviation is less then 10.95%.This accuracy is enough to meet the requirements of gas diffusion emergency rescue.