Research On Filtering Effect Of Large Eddy Simulation Method In Unsteady Numerical Wind Tunnel

With the continuous development of the global economy and the ongoing improvement of people's living standards,people's requirements for the shape and appearance of building structures have further increased,and more and more over-limit structures have continuously emerged.As the representative of over-limit structures,super high-rise buildings and largespan buildings have the characteristics of low mass,large flexibility,low natural frequency,and low damping ratio.They are typical wind-sensitive buildings,which are affected by the irregular atmospheric boundary layer air flow and wind disturbance.Therefore,for structural design,it is of great significance to study and improve the performance of such over-limit structures under wind load.Numerical wind tunnel simulation(CFD)technology is one of the main research methods in the field of structural wind engineering.With its low investment,short simulation cycle,parameter modification boundary,the result is rich in data.The advantages of the flow field have won the favor of many experts and scholars in the field of structural wind engineering.In computational wind engineering,according to research methods,numerical wind tunnel technology can be divided into two types: steady-state numerical wind tunnel technology and non-steady-state numerical wind tunnel technology.Among them,the non-steady-state numerical wind tunnel technology overcomes the shortcoming that the steady-state numerical wind tunnel technology can only obtain the average value,and can obtain the wind load time history results for calculating the equivalent static wind load and comfort analysis,so it is more practical in wind-resistant design.Meanwhile,as the turbulent vortex cluster in the air wind field moving from the entrance to the front of the building(the first third of the watershed area),the effect of the grid model for each wind parameters such as: average wind profile,turbulence profile,pulsating wind speed power spectrum has been studied innovatively.While verifying that the filtering effect is real,it also puts forward corresponding suggestions for the requirements of different parameters in different simulation environments.It provides valuable methods and suggestions for the subsequent research on actual engineering with buildings.While verifying that the filtering effect is real,it also puts forward corresponding suggestions for the requirements of different parameters in different simulation environments.It provides valuable methods and suggestions for the subsequent research on actual engineering with buildings.