Large Eddy Simulation Study On Interference Effects Of Corner Chamfers On High-rise Buildings

Compared with traditional low-rise buildings,high-rise buildings have less lateral stiffness,more flexibility and they are more sensitive to wind load.In order to reduce the wind load on the control of the structure,we usually use pneumatic measures,such as adding to the building Chamfer,etc.However,when the density of high-rise building increases,the interference effect of structure can not be completely ignored.At present,only the square and rectangular cross-section building interference effect value is given in the code,but the corner-cutting high-rise building interference effect is rarely concerned by scholars.In this paper,large eddy simulation method is used to obtain aerodynamic and wind pressure data of high-rise buildings with different working conditions and based on the results of Aerodynamic Coefficients,wind pressure coefficients and interference coefficients,the wind load characteristics,non-gaussian characteristics and interference effects of high-rise buildings with different arrangement are studied.The main research works are as follows:（1）In order to verify the accuracy of numerical simulation method,the flow around square cylinder is verified by simulation test.The aerodynamic coefficients,wind pressure coefficients and strouhal numbers of the square cylinder are compared with the results of wind tunnel tests in the literature,The results show that when the value of y⁺is 2.5,the parameters of the wind field around the square cylinder can be accurately simulated by the large eddy simulation.In order to obtain more accurate simulation results,this paper still control the wall y⁺value less than 1.0 for the subsequent numerical simulation.（2）The wind pressure distribution and Aerodynamic Coefficient Change Law of high-rise buildings with different pitch ratio under typical arrangement are studied,and the Kurtosis and skewness are calculated by time-history curve of wind pressure coefficient,a non-gaussian characteristic criterion is proposed.Finally,the peak factor is calculated by combining the observation extremum method and the full probability iteration method.The results show that When the spacing ratio is 1.5,the greatest disturbance occurs at the corner cutting of adjacent facades,and when the spacing ratio is 8.0,the large disturbance still exists.The critical spacing ratio of tandem operation is2.5～3.0 ahead of schedule.When the spacing ratio is less than the critical spacing ratio,the disturbed building shows a decreasing effect.When the spacing ratio is larger than the critical spacing ratio,the amplification effect of left and right facades is obvious.（3）According to the results of the interference effect of the typical buildings,the distribution of the interference effect of the buildings with arbitrary arrangement and tangent angle is studied.This paper summarizes the aerodynamic interference effects,non-gaussian characteristics and wind pressure interference effects of high-rise buildings with different tangent angles and elevations in different space coordinates,this paper studies the most disadvantageous coordinate of interference effect of high-rise building with chamfer corner,and provides reference for the value of interference factor of this kind of building.The results showed that:The extreme wind pressure,non-gaussian characteristic,flow field and interference effect between high-rise buildings are mainly controlled by crosswind spacing.When the crosswind distance is less than 2.0L,The wind pressure on the surface of the disturbed building is biased,and the high wind pressure is concentrated on the side near the disturbed building.When the crosswind distance is 2.0L～4.0L,the extreme wind pressure,non-gaussian characteristic and interference effect of the building with corner cutting approach the parameters of the unperturbed building gradually.When the crosswind distance is more than 4.0L,the disturbed building is basically the same as the undisturbed building.