The Influence Of Building Cluster Layout On Outdoor Wind-thermal Environment Under The Effect Of Thermal Plume

In recent years,with the advancement of urbanization and the improvement of people's living standards,people have higher and higher requirements for indoor comfort.In order to improve indoor comfort,current research focuses on the improvement of heat transfer performance of buildings and indoor environment protection technology,while the research on the interaction between buildings and outdoor microclimate is very limited.In fact,the ontological characteristics and morphological layout of urban building cluster will have a direct impact on the outdoor wind and heat environment of the building,and then affect the cooling and heat load of the urban building cluster and the control cost of the indoor environment.The study of the influence mechanism of urban building cluster on regional wind-thermal environment is conducive to the comprehensive consideration of energy consumption and regional micro-environment,and the implementation of the optimal design of architectural complex.In this paper,the outdoor wind and thermal environment under the combined action of different building configurations and thermal plumes are simulated and analyzed by combining experimental testing with numerical simulation.First of all,based on the similarity theory,the thermal plume characteristics of individual buildings and buildings reduced scale model experiment was carried out to study,monomer model results show that with the increase of building height,wind speed and temperature on the surface of the building increases gradually,with the increase of distance from facade,air temperature gradually reduced,air flow velocity increases first,then decrease,wall at 1 cm distance reached the maximum wind speed.The results of the model experiment of the building cluster show that the wind speed outside the building cluster increases with the distance from the ground.At the distance of 10 cm from the building cluster,the wind speed presents a parabolic distribution,and the temperature and the wind speed change trends are basically similar,but the temperature difference between different locations is limited.Secondly,a numerical simulation model of the wind-thermal environment under the action of thermal plume and its solution method are established,and the accuracy of the model is verified by comparing the simulation results with the experimental data.The comparison results show that the variation trend of temperature and wind speed obtained from the simulation and the test is exactly the same,and the overall relative error is within 10%.The simulation results are highlyconsistent with the measured results.Then,the physical model of the actual building cluster was established,and the variation law of the outdoor wind-thermal environment was simulated and analyzed under the influence of the thermal plume on the surface of the building in the static wind environment and the morphological layout characteristics of the building cluster.The simulation results show that the layout of the building cluster,the spacing between building cluster and the ratio of height to width have a significant impact on the outdoor wind and thermal environment of the building cluster.When the average space between the buildings is 20 m,the average wind speed induced by the hot plume is the largest,which can reach 0.96m/s.When the average aspect ratio of the buildings is 0.375,the average wind speed induced by the hot plume can reach 1.05m/s.The plume has a small influence on temperature and is concentrated in the surrounding area of the complex.Finally,under the combined action of background wind and thermal plume on the building surface,the variation rules of outdoor wind-thermal environment of building cluster with different building layouts were simulated and analyzed.The results showed that the wind speed in courtyard layout was more evenly distributed when the wind speed was 1m/s.When the average wind speed is 4m/s,all the three layout forms can form channel wind,but the average wind speed of courtyard layout is only 4.5m/s.Under three wind speed and three layout modes,the influence range of thermal plume on outdoor temperature is mainly in the area near the building facade.The study of this paper reveals the characteristics of thermal plume on the building surface and the influence mechanism of building cluster layout on the regional wind-thermal environment.The research results can provide theoretical basis and technical support for the optimal design of urban building cluster.