Outdoor thermal environmental research of the mountainous city by GIS

The study of urban outdoor thermal environment was carried out in one of the mountainous cities by using geography information system(GIS) technique which is connected with predicting and evaluating models for the outdoor thermal environment, monitoring data and simulating data. A prediction and evaluation system were set up. A typical mountainous city, i.e., Yunyang city in Chongqing in China, was taken as an example, its urbanization trend and population growth was predicted and evaluated. The heat island intensity and its trend were simulated, the temperature field, velocity field and the humidity field were analyzed. The results show that GIS is an effective tool to deal with the outdoor thermal environment, especially for the mountainous cities with special geographical particularities. GIS can be used in the environmental management and the city planning especially for the mountainous cities.

Urban Spatial Form Optimization Strategies Based on the Principle of Climate Adaptability of Regional Architecture: A Case Study of Traditional Cave Dwelling Villages in Northern Shaanxi Province

A multitude of climate-adaptive design approaches are embedded in regional architecture,which have a positive impact on addressing the deformed development of urban spatial patterns and the dual challenges of climate and resources.This paper examines the principles of climate adaptability embedded in the site layout and spatial organization characteristics of traditional cave dwelling villages in northern Shaanxi Province.The extracted climate adaptability principles are summarized,and the resulting design strategies that are well-suited to the contemporary urban space form are presented.Through analysis,it can be observed that traditional cave dwelling villages in northern Shaanxi are predominantly situated on south-facing slopes in proximity to water at low altitudes.These villages are characterized by compact building groups and east-west development,which is constrained by the elements of mountains and rivers.A two-level street system is generated,comprising streets parallel to the contour line and roadways perpendicular to the contour line.This results in the formation of a courtyard form enclosed by mountains.Such site layout and spatial organization exhibit excellent climate adaptability with regard to heat,ventilation,and wind storage.In light of the aforementioned considerations,the following urban spatial form design strategies are put forth:①the topographic height difference can be exploited to obtain sufficient sunshine;②the group shape can be optimized in order to reduce building energy consumption;③the best orientation of the building can be chosen to take account of both winter and summer conditions;④the height and length can be combined in order to form natural masking;⑤the D/H ratio of streets and roadways should be controlled to achieve a balance between heat gain and cooling of groups;⑥vents should be set appropriately to optimize group ventilation;⑦climate buffers should be established to increase the level of climate response.

Prediction model of the radiation from ground surface to the occupant in outdoor space

The outdoor ground radiation including the emitted radiation and reflected radiation plays an important role in the outdoor thermal environment. In this paper, based on the hypothesis of that the occupant body can be equivalent to a human cylinder and the outdoor ground surface is diffusive for radiation, a mathematical model is advanced to describe the radiation from the ground surface to the occupant. Through theoretical analysis of the mathematical model, general formulas for calculating the radiation arriving at the occupant from an annular ground surface and infinite ground surface are obtained. It shows that, the radiation from ground surface to the occupant depends on the surface temperature, reflectivity and emissivity, the arrange within the radius of 8.0m encircling the occupant can be defined as the dominant radiating area which radiates 90% radiation to the occupant. The radiative potentials of different pavement surface such grass, asphalt concrete surface, granite slab surface, terracotta bricks, colored concrete interlocking blocks are also compared with the datum measured by Tan Slew-Ann and Fwa Tien-Fang in Singapore, it shows that, in the summer sunny day, grass surface radiates more radiation in the morning but less in the afternoon than other pavement materials. Finally, discussions of reducing the radiation of outdoor ground surface are presented and main conclusions are drawn for improving the outdoor thermal environment.

Optimal design of vegetation in residential district with numerical simulation and field experiment

Vegetation plays a key role in improving wind environment of residential districts,and is helpful for creating a comfortable and beautiful living environment.The optimal design of vegetation for wind environment improvement in winter was investigated by carrying out field experiments in Heqingyuan residential area in Beijing,and after that,numerical simulation with SPOTE(simulation platform for outdoor thermal environment) experiments for outdoor thermal environment of vegetation was adopted for comparison.The conclusions were summarized as follows:1) By comparing the experimental data with simulation results,it could be concluded that the wind field simulated was consistent with the actual wind field,and the flow distribution impacted by vegetation could be accurately reflected;2) The wind velocity with vegetation was lower than that without vegetation,and the wind velocity was reduced by 46%;3) By adjusting arrangement and types of vegetation in the regions with excessively large wind velocity,the pedestrian-level wind velocity could be obviously improved through the simulation and comparison.

世博国家电网馆半室外空间被动式环境控制研究

本文对世博国家电网馆半室外空间进行了被动式环境控制设计，采用建筑自遮阳、风压强化自然通风、太阳烟囱热压自然通风、细水雾降温组合的方案，以改善参观人员的舒适度。使用CFD模拟、多区域网络法和能量平衡法计算了建筑风压贯穿通风、太阳烟囱热压通风和细水雾降温的效果。选取当前通用的基于舒适标准和安全标准的室外热舒适评价模型SET和WBGT，对舒适度改善的效果进行了评估。研究结果表明，采用被动式环境控制设计后，世博会期间统计（典型年气象参数）不满足舒适（SET〉30℃）小时数从901（20％）降至154（3％），不满足安全（WBGT〉32℃）小时数从203（5％）降至10（0％）。

环境性能驱动下热带季风气候区高层宿舍组团塑形方法研究——以三亚崖州湾科技城公共教学区宿舍楼地块为例

近年来,城市人居环境日益恶化,组团建筑的环境性能提升逐渐成为国内外建筑师面临的重要研究课题。随着计算机软件技术的发展,风、光、热环境性能可视化模拟分析技术逐渐成熟,环境性能驱动设计在组团塑形中被逐步推广。宿舍楼项目位于海南三亚西部的崖州湾科技城公共教学区,采用了“策略—总体—建筑—表皮”逐层递进的设计路线。本文试图通过该项目,探讨一种环境性能分析驱动下高层宿舍组团塑形新方法。

不同环境风速下建筑外空调室外机热环境分析

布置在建筑物凹槽内的室外机,在环境风速作用下,其运行环境会发生变化。有时恶劣的热环境甚至会造成室外机无法正常工作。本文对不同环境风速下的高层建筑凹槽内空调室外机热环境开展研究,确定了侧面、正面风向下,室外机正常工作所能承受的临界风速。分析了不同风向条件下,凹槽内气流速度场、温度场,并给出温度沿高度方向的变化规律。研究发现,侧面风带走冷气流和楼层间热气流短路,都会造成上层进风温度升高;侧面吹风时,凹槽内上下游列室外机不同的热环境,是由凹槽内特殊旋涡流动导致的。对于正面吹风情形,临界风速应小于0.5 m/s。本研究探明了不同环境风速下高层建筑室外机热环境变化规律,可为考虑风速条件下室外机的选用安装提供参考。

Field measurements on microclimate in residential community in Guangzhou,China

Taking a certain housing in Guangzhou as an example,we conduct the field measurement of the microclimate at fixed points for air temperature,relative humidity,black globe temperature and wind speed,etc.We investigate the effects of manmade lake,shade of trees and ground surface character on outdoor thermal environment,and make a quantitative analysis on the weighting position of the landscape design factors in design behavior.The study intends to explore a method to improve the thermal environment of residential quarters by changing the corresponding factors.