车辆对城市街谷热环境的影响研究

发布时间：2018-11-28 17:21

【摘要】：随着城市化进程不断加快，人们的生活水平日益提高，汽车的购买力与日俱增，城市机动车的保有量正迅猛地增长。数量庞大的车辆犹如移动的散热器，散发出的大量热量严重影响着城市街谷下垫面的热环境。街道是人和车辆最为集中的区域，两者的距离、高度均较接近，此时车辆的排热最能直接地影响到行人的热舒适性。因此，研究街谷中车辆对热环境的影响具有重要意义。本文以广州城市道路及车辆作为主要研究对象，采用现场实测和数值模拟相结合的研究手法，全面地了解和评价了街谷中车辆对热环境的影响。主要研究了以下内容：首先，在广州城市道路实地调研了交通高峰期时段车流量、车型等方面的情况，并根据调研结果选取了研究实测的车型。其次，进行了实测实验，对车体自身和周围的热环境进行了全面的测试，得到了车辆表面不同区域的表面温度、车体周围空气温度、风速风向等方面的逐时变化情况。第三，将实测实验所采集的数据进行分类整理，着重分析了单体车辆散热与周围空气温度变化的关系。另外，对车体表面温度和周边空气温度进行了线性拟合，表明了两者具有高度的相关性。第四，在总结前人工作经验的基础上，以前期实测实验作为依托，建立起三维物理模型，通过Fluent软件对车辆周围热环境进行数值模拟，并对比分析了模拟结果与实测结果，发现实测与模拟的结果较为吻合，确定了模拟结果能够满足工程精度的要求。最后，，采用Fluent软件对单体车辆、双台车辆、多台车辆分别进行不同主导风向的模拟计算，并分析了在行人高度平面（1.5m高度平面）和机动车主要热源高度平面（0.5m高度平面）的温度变化情况。根据实测和模拟的研究结果，本文归纳提出了缓减车辆恶化街谷热环境的可能性措施及优化方法，为今后城市街谷热环境优化设计提供参考指引。
[Abstract]:With the acceleration of urbanization, people's living standard is improving day by day, the purchasing power of cars is increasing day by day, and the number of urban motor vehicles is increasing rapidly. A large number of vehicles, like moving radiators, emit a great deal of heat that seriously affects the thermal environment of the underside of the city valley. The street is the area where people and vehicles are most concentrated, and the distance and height of both are close. At this time, the heat discharge of vehicles can directly affect the thermal comfort of pedestrians. Therefore, it is of great significance to study the influence of vehicles on the thermal environment in the street valley. Taking Guangzhou urban roads and vehicles as the main research object, this paper comprehensively understands and evaluates the influence of vehicles in the street valley on the thermal environment by the combination of field measurement and numerical simulation. The main research contents are as follows: firstly, the traffic flow and vehicle type during the rush hour are investigated in Guangzhou city road, and according to the research results, the actual vehicles are selected. Secondly, the experimental results are carried out, and the time-dependent variations of surface temperature, air temperature, wind speed and wind direction in different areas of the vehicle surface are obtained by means of a comprehensive test of the body itself and the surrounding thermal environment. Thirdly, the data collected from the experiment are classified and sorted, and the relationship between the heat dissipation of the single vehicle and the change of ambient air temperature is analyzed. In addition, the surface temperature of the car body and the ambient air temperature are fitted linearly, which shows that they have a high correlation. Fourthly, on the basis of summing up the previous work experience, a three-dimensional physical model is established based on the experimental results, and the thermal environment around the vehicle is simulated by Fluent software, and the simulation results and the measured results are compared and analyzed. It is found that the measured results are in good agreement with the simulation results, and the simulation results can meet the requirements of engineering accuracy. Finally, Fluent software is used to simulate the different dominant wind direction of single vehicle, double vehicle and many vehicles. The temperature variation in the pedestrian height plane (1.5m height plane) and the vehicle main heat source height plane (0.5m height plane) is analyzed. Based on the measured and simulated results, this paper summarizes the possible measures and optimization methods to mitigate the deterioration of the thermal environment in the street valley, which provides a reference for the optimization design of the thermal environment of the urban street valley in the future.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU119.4

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