Study On The Impact Of Underlying Surface On The Thermal Environment Of Children’s Activity Space In Hangzhou Residential Area

In recent years,urbanization has been continuously advancing,and the thermal environment issues on the underlying surface of cities have been intensifying.With the proposal of the "Children Friendly City" strategy,children’s activity environment has received more attention.As the main carrier of children’s daily activities,it is worth exploring how to design children’s activity spaces in residential areas.The purpose of this study is to study the impact of different underlying surfaces on the thermal environment of children’s activity space in residential areas,and propose optimization strategies based on field survey and computational fluid dynamics(CFD)simulation.The main research content is as follows:Firstly,in order to intuitively understand the current conditions of children’s activity spaces in Hangzhou residential areas.1)Conduct research on children’s activity spaces in existing residential areas in Hangzhou,and summarize the types and layout of underlying surfaces,as well as the ways and times of children’s activities;2)Using site data to construct a numerical model for thermal environment simulation experiments,the simulated experimental results of six types of pavement surface temperatures and various thermal environment parameters in children’s activity spaces were compared and analyzed with the measured results.The feasibility of the numerical model was verified,and it was found that there were significant differences in surface temperatures among different pavement materials.Secondly,in order to further explore the impact of different underlying surfaces on the thermal environment of children’s activity spaces in residential areas.Based on on-site measurement results,perform CFD simulation and evaluate thermal comfort using the Universal Thermal Climate Index(UTCI).Research has found that: 1)Grassland has a significant cooling and moisturizing effect,but it has a weakening effect on wind speed compared to other materials;The higher the ground temperature and height of pavement,the weaker the influence of pavement on various factors;2)The children’s UTCI above the six paving materials,from small to large,is: grass,plastic,sand,wooden board,brick,and asphalt concrete,with little impact on adult UTCI;3)As the thermal properties of different pavements increase,the air temperature decreases,but the impact on wind speed and humidity is relatively small;4)The improvement effect of different pavement thermal property optimization on children’s UTCI from large to small is reflectivity,specific heat capacity,emissivity and thermal conductivity.Therefore,it is recommended to use high refractive index coating and light color coating;5)The shading and cooling effects of buildings and plants are significant.Finally,propose optimization strategies for the underlying surface of children’s activity spaces in residential areas.Propose corresponding improvement plans for the pavement,buildings,and plants in the underlying surface,take the actual children’s activity space as an example for optimization design,and compare the thermal environment before and after optimization through CFD simulation.