Wind Environment Simulation Of Building Groups Based On CFD

Wind,as a special fluid,runs through the whole process of civil engineering survey,design and construction.In different engineering stages,according to the actual needs of the project,the research focus of wind is different.In the survey stage,it mainly studies the influence of wind direction and wind speed on the project;in the design stage,it needs to focus on the effect of wind field formed by the wind field,that is,the focus is to analyze the possible impact of wind field on adjacent buildings,which is also the content of this paper.In the construction stage,for different types of buildings(structures),wind research is not the same.For example,in the bridge construction,it is necessary to study the vibration frequency of wind to avoid damping resonance of the bridge,and to consider the influence of wind load on the stability of the bridge structure;in the tunnel engineering,the wind flow is mainly studied to determine the reasonable tunnel ventilation and smoke exhaust method;In the indoor and outdoor design of buildings,it is often necessary to consider the dynamic disturbance of wind.It can be seen that whether it is civil construction or architectural design,we need to pay close attention to the special impact of wind on buildings.Generally speaking,the flow of wind(such as wind speed,wind direction,wind pressure and other wind environmental parameters)will have a greater impact on building planning and design.Therefore,in architectural design,it is often necessary to give priority to the effect of wind on buildings.In the design of residential buildings,it mainly refers to the basic requirements of building ventilation and heat dissipation.Generally speaking,good ventilation and heat dissipation conditions can provide users with a higher degree of comfort,which not only realizes the maximum use of building functions,but also conforms to the "people-oriented" basic principle advocated in architectural design in recent years.Therefore,building wind environment design as an important part of architectural design,in-depth research is of far-reaching significance.Based on the previous research results and the climate conditions of Wuhan in recent ten years,this paper selects a university campus in the northwest of Wuhan as the research object.Based on the engineering surveying and mapping data obtained from field investigation,the Standard turbulence model is selected to simulate the wind field formed in the campus and its surrounding areas with the help of FLUENT software under the knowledge background of classic Navier-strokes equation.The specific research contents are as follows:(1)On the basis of consulting the climate statistical data of Wuhan in recent ten years,this paper studies and analyzes the basic dynamic law of the wind flow around the existing buildings in the campus and the flow characteristics of the wind field formed;(2)According to the existing research results and the actual situation,under the proposed working conditions(according to the standard residential building plane size and floor height setting),the impact of four building layouts on the wind environment of the building group is studied and discussed;(3)Wind field simulation of existing buildings in Jinyinhu campus.By dividing different wind profiles,the wind environment of campus buildings in Z,X and Y directions is simulated,and the wind pressure and wind speed changes of existing buildings at different heights(such as pedestrian height of 1.5m)are studied and analyzed;(4)As mentioned above,based on different wind profiles,CFD simulation is carried out for different construction schemes of new campus projects.Referring to the roughness coefficient values of different contact surfaces,this paper focuses on the wind speed at the entrance of Jinyin Lake campus and the windward and leeward sides of each building,and the reduction speed when passing through different contact surfaces.In conclusion,the CFD numerical simulation shows that in the three proposed schemes,the wind speed at different building heights in scheme 1 tends to be stable and within 1.248m/s.The overall positive and negative wind pressure values are respectively stable within-0.891 pa and 0.385 pa,and the positive and negative pressure difference is basically within the specified limit of 5pa.From 0.5 m below the pedestrian height to 1.5m above the pedestrian height,the wind pressure is basically stable and the numerical change is small.Under the same conditions,the wind environment optimization effect of scheme 1 can be given priority.The wind flow frequency of scheme 2 and 3 will be greater than that of scheme 1,which will have a greater impact on the wind environment of existing buildings on campus.And the positive and negative wind pressure difference between the windward and the windward side of scheme 2 and 3 exceeds the specification limit of 5pa,which should be appropriately adjusted to optimize the overall campus wind environment.