Research On Gust Wind Tunnel Simulation Of Wind Effect In High-rise Buildings

The pressure measurement test of the wind tunnel scale model is an important means to obtain the wind effect information of the structure and guide the structure design.However,the traditional wind tunnel test relies on passive turbulence simulation technology to simulate the turbulence characteristic parameters of the atmospheric boundary layer.The turbulence characteristic parameters obtained by the simulation do not match.For example,the turbulence integral scale cannot be accurately simulated.At the same time,there is a positive correlation between the turbulence integration scale and the turbulence intensity.It is difficult to distinguish the effects of the two in traditional experiments.The active gust wind tunnel can adjust the turbulent integral scale in the flow field by mechanical devices,so as to achieve the purpose of distinguishing the influence of turbulence intensity and turbulent integral scale on the wind effect of high-rise structures.Based on active gust wind tunnels,three types of flow fields with geomorphic type B and different turbulence characteristics were simulated,A high-rise building model with a scale ratio of 1: 300 is used for the pressure test,the full text works was as follows:(1)For the wind pressure coefficient on the surface of high-rise buildings,the turbulent integral scale has little effect on the average wind pressure coefficient,while the fluctuation and peak negative pressure coefficient(absolute value)are positively related to the turbulent integral scale,while the turbulence intensity is related to the structure surface wind pressure coefficient(absolute value)positive correlation,The influence of turbulent integral scale on the downwind drag coefficient is negligible.The root coefficient variance of the drag coefficient is positively correlated with the turbulent integral scale,while the turbulence intensity is positively correlated with the drag coefficient.For the lift coefficient,the turbulent integral scale and the lift coefficient in the oblique wind direction angle There is a positive correlation.When the wind direction is perpendicular to the front of the structure,the integral scale has a small effect,and the effect of turbulence intensity on the lift coefficient has a small relationship with the wind direction angle,showing a positive correlation trend.(2)The increase in turbulence intensity and turbulent integration scale has an effect on the correlation between horizontal and vertical wind pressures on the windward and leeward side,and the turbulence integration scale has a more significant increase in correlation;The turbulent integral scale has a positive correlation with the turbulence intensity and the root-moment root variance of the downwind base,while the turbulence integral scale has the opposite effect,and the turbulence intensity has a smaller effect.(3)Comparing the proportions of the displacements along the crosswind direction in various working conditions,it is found that the proportions of the first-order displacements along the wind direction are all above 90%,and the first-order displacements across the wind direction are above 80%.It shows that the second-order displacement should be considered when calculating the lateral displacement of the structure for safety reasons.(4)Comparing the three methods of GLF,IWL and MGLF,the calculation result of MGLF method is the most conservative.calculation result of the second IWL method of the GLF method is the smallest.it is found that the sensitivity of the GLF and IWL methods to the turbulence intensity is greater than the turbulence integral scale,and the MGLF calculation results are more affected by the turbulence integral scale.Comparing the effects of turbulence characteristics on the equivalent pulsating wind load calculated by each method.