|摘要: ||本研究主要是在使用大渦模擬法去模擬風場中高寬比1:3之方柱所受的風載重，對風載重的模擬結果會做結構反應分析並對照風洞實驗室的實驗結果；探討方向分為三個部份。 |
This study is the wind load of the square shaped building with the aspect ratio 1:3 were simulated by large-eddy simulation method. The simulation results of wind load and structural response analysis were compared with those of wind-tunnel test. There are three parts would be study.
First, it divide grids around the square column mainly. We set the square column at 8D downstream of the inflow boundary, and gives the uniform flow of Re=1×105 in inflow. The results of this study, wind pressure is agree in the windward, but bigger than wind-tunnel test in the leeward. These causes the drag force coefficient to be big. Because the results is closed to the simulation of predecessor. The Strouhal number and lift coefficient close experimentation value. So it confirmed the grids.
Second, a fully developed boundary layer flow initially generated in the wind tunnel was selected as the target flow field. Additional a fully developed boundary layer flow of the wind tunnel test, i.e., mean wind speed, kinetic energy and dissipation rate. And additional the surface shear was set on the ground to represent the effects of wind tunnel surface roughness elements. The upper twe-third of the profile is also agreed well with target flow. The flow in the lower one-third of the calculation domain has excessive energy dissipation, with RMS wind speed lower then the target flow field.
In the third stage of this project, the 1:1:3 square shaped building model was installed at 8D downstream of the inflow boundary. All the initial conditions are set up with the second part of the same, i.e., add mean wind speed, kinetic energy and dissipation rate at the inflow boundary, and shear stress on the ground. The result compare with wind tunnel test,the mean drag force coefficient and RMS drag force coefficient value are found 23% larder than wind tunnel measurement, and lift coefficient is too large. The Strouhal number is 0.09.