Numerical Wind Tunnel Simmulation Of High-Rise Buildingds

With the rapid development of the social economy and construction level,high-rise buildings in the city have become commonplace.They have greatly eased the pressure on land resources,improved the working and living environment,and are the backbone of the development of modern cities.In fact,the construction of high-rise buildings is not just a superposition of the number,but also to fully consider the interaction of buildings,especially the impact of horizontal wind pressure.Compared with the single building,the wind field environment of the group building is more complicated,and the distribution law of the surface wind pressure varies greatly.Therefore,it is necessary to conduct more in-depth research and analysis on the building group.Based on the FLUENT software,the numerical wind tunnel simulation under different conditions is carried out on the buildings consisting of four high-rise buildings to explore the distribution of surface wind pressure and wind pressure coefficient of the building group.The main research work is as follows:Through reviewing relevant literatures at home and abroad,the research status of building wind engineering is reviewed and summarized,including four aspects:building wind environment,structural wind load,structural wind load and load disturbance effect.Explain in detail the basic theory and basic methods of numerical wind tunnel simulation,and highlight the key steps.The classical CAARC model is taken as an example to verify the feasibility and reliability of the proposed method.A single building model with a geometric dimension of 20m×20m×100m was established,and a two-tower building model and a group building model were established based on it.Then,numerical wind tunnel simulations of the same conditions were carried out for the three models,and the distribution of surface wind pressure and wind pressure coefficient of the building under three conditions was obtained.Numerical simulations of the buildings were carried out using six different wind speeds,with a minimum wind speed of 10 m/s,a maximum wind speed of 35m/s,and a reference height of 10m for wind speed.The simulation results show that the surface wind pressure and wind pressure coefficient of the building group change with the wind speed.The research shows that as the wind speed increases gradually,the gradient of the wind pressure coefficient of the upstream buildings decreases gradually,and the windward side coefficient value with higher wind pressure coefficient decreases,while the leeward side coefficient value with lower wind pressure coefficient increases;downstream The gradient of the wind pressure coefficient of the building gradually increases,and the wind pressure coefficient of the roof surface,the windward surface and the two sides increases,and the wind pressure coefficient of the leeward surface decreases.As the wind speed increases,the surface wind pressure of the building group increases.Rapidly rises.Four different layouts of the building group model were obtained by changing the lateral spacing of the building.In this paper,?₁??₂?is defined as the ratio of the cross-wind distance of the upper?lower?building to the width of the building.The four layouts are?₁=1,?₂=1;?₁=1,?₂=3;?₁=3,?₂=1 and?₁=3,?₂=3.The numerical wind tunnel simulation under the same conditions was carried out for the four different layouts of the building group model,and the results were compared and analyzed.Studies have shown that when both?₁ and?₂ are 1,the maximum positive pressure zone of the building group is distributed on the windward side of the upstream building,while the largest negative pressure zone is distributed on the roof and inner side of the upstream building;?₁=1,?₂=3,the maximum positive pressure zone of the building group is distributed on the windward side of the upstream building,and the largest negative pressure zone is distributed on the outer side of the downstream building;when?₁=3,?₂=1 The maximum positive pressure zone of the building group is distributed on the windward side of the upper and lower buildings,while the largest negative pressure zone is distributed on the inner side of the downstream building;when?₁=3,?₂=3,the largest of the building group The positive pressure zone is distributed on the windward side of the upstream building,while the largest negative pressure zone is distributed on the roof surface of the upstream building.Numerical simulation of the building group using three different sediment carrying sands,the volume fraction of the sand phase is 0.5×10^-5,1×10^-5,2×10^-5.The variation of the surface wind pressure and wind pressure coefficient of the building group with the sediment concentration is obtained.The results show that with the increasing volume fraction of sand phase,the surface wind pressure and wind pressure coefficient of the building group show an overall upward trend.Among them,the leeward side of the upstream building,the roof surface and the leeward side of the downstream building are less affected by the sand grain phase,and the remaining faces are greatly affected.