Numerical Simulation Of Wind-induced Snow Drift Based On Experimental Similarity Theory

The continuous occurrence of disasters caused by the blizzard movement has brought great loss to people’s life and property.In order to minimize the disaster loss caused by snow,it is necessary to study the characteristics of snow movement in many aspects.At present,wind tunnel test is a reasonable research method for drift motion of snow caused by wind.It is very important for the research and selection of similarity criterion to get reliable results.Firstly,according to the mechanism of wind snow movement,this paper introduces the similarity criteria and test materials of wind tunnel test,summarizes the research results of scholars in recent years on the similarity criteria and test materials,puts forward several main similarity conditions that need to be met to reach consensus at this stage,and preliminarily selects the appropriate test materials.On the basis of the above work,the finite element model of wind tunnel is established by using the finite element software FLUENT for numerical simulation test,and the simulation parameters are determined by summarizing some similar criteria,and the simulation effect of selected materials is preliminarily discussed.Then,the wind-induced snow drift on the surface of the classic high and low roofs is simulated,and a method of equivalent particle velocity nephogram to dimensionless accumulation curve is proposed The test results of tsauchiy are taken as the standard,and the comparative analysis is carried out.The influences of wind speed,initial laying thickness,particle type and selection of similar criteria on the simulation results are discussed,which provides reference for the future wind tunnel test design.Finally,according to the above research results,this paper analyzes the factors of the wind-induced snow drift of the sloping roof,discusses the motion law of the wind-induced snow drift,summarizes the design characteristics of the sloping roof,and provides the theoretical basis for the snow resistance design of the sloping roof.The main contents of this paper are as follows:1)Based on the similarity theory of wind-induced snow drift wind tunnel test,this paper summarizes the research results of similarity criteria in recent years,it is pointed out that the similarity of geometry,wind profile,angle of repose,Inertia Force and gravity ratio,drag force and inertia force ratio and particle jump process are the main similarity conditions.The advantages and disadvantages of small,medium and large density materials were compared and analyzed,and it was pointed out that large and medium density materials should be given priority in the experiment The large-density edible salt was used as the secondary simulation material.2)With fluent The wind speed ratio of sawdust,artificial snow and real snow material is 10:7:5 under the condition of equal distance simulation under the condition of falling drift,and the similarity criterion of particle deposition volume under the condition of stacking drift is selected to determine the similarity of each material under the condition of stacking drift The ratio of exercise time is:: = 1.5:1.84:1.It is found that the wind-induced motion of artificial snow is closer to the real snow.3)Based on the obtained wind speed ratio and time ratio,fluent is adopted The software calculates and analyzes the wind-induced snow drift of the low roof of the high and low roof buildings,puts forward the method of equivalent transformation of the velocity cloud chart of particles into the stacked dimensionless curve,and analyzes the variables of the thickness,wind speed and materials.It is found that the simulation effect of the real snow,artificial snow and edible salt are similar,and summarizes the similar conditions of several materials,which proves the immeasurable The two similarity criterions,i.e.the similarity of wind speed and the similarity of particle deposition volume,have good similarity effect in the test simulation,and they are not affected by the material density,so they can be used in the test.4)Based on the obtained finite element modeling method,test similarity theory and dimensionless accumulation curve,this paper analyzes the factors and variables of wind-induced snow drift of sloping roof.Taking building height,roof slope angle,particle type,particle laying thickness,wind speed and wind direction as variable parameters,it is found that the simulation effect of man-made snow and its representative medium density particles is better,and when the building height is smaller The larger the slope,the smaller the initial accumulation thickness,and the smaller the wind speed,the more obvious the accumulation effect of snow particles.It is necessary to focus on the influence of snow load on the roof area.