Method for simulating influence of real trees on migration of street pollutants

Abstract

The invention discloses a method for simulating the influence of a real tree on the migration of street pollutants, and the method comprises the steps: selecting the real tree, scanning the real tree to obtain the point cloud data of the tree, and reconstructing the branch and trunk entities of the tree according to the branch and trunk point cloud data information of the tree; a numerical simulation grid with tree branches and streets as a system is obtained; on the grids, mass, momentum and turbulence equations of airflow flowing in the street and a pollutant convection and diffusion equation are solved in a coupling mode, and particularly, a crown resistance source mathematical model is solved according to distribution of tree leaf point cloud data; and finally, the pollutant transport behavior and the spatial distribution of the pollutants under the influence of the real trees are obtained. According to the method, starting from three-dimensional point cloud data of a real tree, the difficulties of extraction and modeling of tree branches, accurate mapping of a crown resistance source and the like are solved; a real tree-wind-pollutant diffusion integrated numerical model is established, and migration and distribution of pollutants in a street under the influence of trees are predicted more truly.

Description

technical field [0001] The invention relates to the technical field of the influence of trees on the migration of street pollutants, in particular to a method for simulating the influence of real trees on the migration of street pollutants. Background technique [0002] The indoor and outdoor airflow characteristics and pollutant distribution on both sides of the street affect the health of the people who work, live and live in the street. As an important green plant in the street, trees play an important role in regulating the temperature in the street and purifying the air. [0003] At present, the research on the mechanical behavior of street air and pollutant transport under the influence of trees focuses on wind tunnel tests, numerical simulations and field measurements. Numerical simulation technology has the advantages of less resource consumption and more information acquisition. It is used to predict the transport and diffusion of pollutants in streets under the in...

AI Technical Summary

Problems solved by technology

[0007] In addition, there are discontinuous and non-uniform distributions of leaves in the canopy, and the vegetation layer resistance source item loaded uniformly on the entire canopy area (mostly cuboid) cannot reflect this feature;

[0008] Finally, the branches of the tree entity hinder the spread of pollutants, and the existing technology ignores the obstruction effect of the tree entity branches on pollutants

[0009] In summary, when the existing technology simulates the movement of street pollutants under the influence of trees, it either does not consider the blocking and shearing effects of the tree branches on the airflow, or does not consider the shape of the real trees, and lacks the simulation process. Real trees are completely and accurately described and represented

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