Study On Wind Load Characteristics Of Spherical Storage Tank Based On Wind Tunnel Test

Spherical storage tanks are widely used in various industries due to their many advantages such as material saving,simple structure,low cost and low investment.The continuous improvement of the manufacturing level of spherical tanks in various countries promotes the development of large-scale and complex spherical tanks.Spherical tank is a thin shell wind sensitive structure,and China is the country suffering the most severe wind disaster every year in the world.Therefore,the research on the wind load characteristics of spherical tank is particularly important for the wind resistance safety of spherical tank and the prevention of wind disaster leakage accident of spherical In this paper,wind tunnel tests are carried out on the rigid model of spherical storage tank with geometric scale ratio of 1:50,and the wind load characteristics of spherical storage tank under different working conditions are studied.In addition,in order to simplify the statistical analysis of wind load on spherical storage tanks,the average wind pressure coefficient distribution in the super critical range is modeled by subsection formula,which can be used as a reference for subsequent projects.The main research contents of this paper are as follows:(1)Based on the wind tunnel pressure measurement test of rigid model of spherical tank with different number of support columns,the variation laws of wind coefficient and wind pressure coefficient of spherical tank with Reynolds number Re under different columns are given.Results show that:in the uniform flow,Re=7.38×10~5,the 4-pillar smooth spherical tank will have the phenomenon of flow transition.The increase in the number of support columns can delay the occurrence of the flow transition phenomenon.(2)Based on the uniform flow and the rigid model wind tunnel test of the spherical storage tank in the A-type wind field,the effects of different wind fields on the wind coefficient and wind pressure coefficient of the spherical storage tank are given.Results show that the average wind pressure coefficient of the windward area of the spherical storage tank does not change in different wind fields,but the central area and the leeward area will be subject to a larger average wind load in the A-type wind field,and the spherical storage tank will experience a larger average wind load in the A-type wind field.The field is subjected to more pulsating wind loads.(3)Based on the wind tunnel test of rigid model of spherical tank with different surface roughness,it is found that the distribution characteristics of average and fluctuating wind load of spherical tank with surface roughness are similar to those of smooth spherical tank at hypersonic critical Reynolds number.(4)The similarity coefficients C_S and C_K are used to quantitatively describe the similarity of wind load distribution characteristics of spherical storage tanks under different Reynolds numbers and hypersonic critical Reynolds numbers.Results show that in uniform flow,when Re>4.0×10~5,the 20 strut spherical tank with surface roughness of 0.004 can simulate the distribution of hypersonic critical Reynolds number wind load.In class a wind farm,for 20 strut spherical tank,the spherical tank with surface roughness of 0.002 is Re>2.0×10~5 can simulate the wind load distribution of super critical Reynolds number,while for the spherical tank with surface roughness of 0.004,the required Reynolds number is lower.The shape coefficients of each zone of spherical tank at hypersonic critical Reynolds number are given.Based on the average wind pressure coefficient distribution fitting formula,the average wind pressure distribution model of spherical tank at hypersonic critical Reynolds number is established,which provides a reference for subsequent research and analysis.