| Thanks to emergence of the high strength materials with light weight and newtechnologies, there are an increasing number of ultra high-rise buildings appearing indowntown of big cities. Many of them are twin-towers styled. The difficulty for windresistant design of ultra high-rise buildings lies in the estimate of wind load. In thedetermination of wind load, the load code of China only provides the method todetermine the wind load of single building while the effect on wind load caused bysurrounding buildings, complex mountainous terrain and neighboring building issimplified considered. It’s not sufficient to satisfy safety and comfort criteria for ultrahigh-rise buildings with large flexibility. Therefore wind tunnel test and numericalsimulation are needed to estimate wind load and conduct design.According to different method to solve turbulence problems, numerical simulationmethod of CFD can be classified into Direct Numerical Simulation (DNS), Large EddySimulation (LES), Reynolds Averaged Numerical Simulation (RANS). Large EddySimulation is a method combines accuracy with efficiency. This article is based on LESand wind tunnel test.The writer conducts research on wind load of ultra high-risebuildings.The main research contents of this paper are as follows:①If fluctuating wind flow of numerical wind tunnel inlet meets target wind fieldcharacteristics determines the result of LES. It also makes simulation of inlet boundaryconditions a key issue in LES. In this paper, the harmonic synthesis method is chosen tosimulate fluctuating wind flow of numerical wind tunnel inlet. LES is conducted byusing CFD software—FLUENT. Compare wind field characteristic at different positionof numerical wind tunnel with code. Then verifies the feasibility to simulate thefluctuating wind flow and its approximation of real wind field.②The project background of wind tunnel test is Chongqing Oriental InternationalPlaza. Four working conditions and32wind angles for each is conducted in the test.The characteristic of shape coefficient, fluctuating wind pressure coefficient,aerodynamic coefficient and wind load spectrum are compared. Study is carried on theinfluence on wind load characteristic caused by surrounding buildings, mountainousterrain. The result can be used as a guidance for engineering design. ③Simulate fluctuating wind flow of numerical wind tunnel inlet by usingharmonic synthesis method and conduct large eddy simulation of Chongqing OrientalPlaza by using FLUENT. Conduct analysis of the flow characteristic around thebuilding, distribution of mean wind pressure coefficient, characteristic of aerodynamiccoefficient and wind load spectrum. Then compare the wind load result of numericalsimulation with wind tunnel test. |
