Tropical cities are exposed to high air temperature and relative humidity throughout the year, causing pedestrian thermal discomfort. In this work, we present an evaluation of the impact of urban geometry on the outdoor thermal comfort (OTC) in Singapore, focusing on a new mixed-use high-rise development. Different urban design strategies/scenarios have been analyzed: two block forms, four street orientations (N-S, E-W, NE-SW, NW-SE), four street aspect ratios (from 1.5 to 3.5) and three building height profiles (arrangement of buildings based on height).

The study is based on modelling techniques. Each scenario was analyzed for seven representative weather conditions during the year. The results are analyzed with specific metrics that take into account the spatial and temporal OTC variations. The results are conditioned by prevailing low winds and high frequency of cloudy days. The best OTC levels are observed on high street aspect ratios (2.5–3) and on N-S oriented streets. Although, on a yearly perspective the streets oriented NE-SW show the worst OTC performance, deviation from the acceptable range is not high. Higher differences between street orientations are encountered for specific weather types. The outcomes provide adequate urban parameters for high-rise developments to improve OTC in hot and humid tropical regions.

热带城市一年四季都暴露于高温和相对湿度的环境中，导致行人热不适。在这项工作中，我们对新加坡的城市几何形状对室外热舒适性（OTC）的影响进行了评估，重点是新的混合用途高层建筑。分析了不同的城市设计策略/场景：两个街区形式，四个街道方向（NS，E -W，NE-SW，NW-SE），四个街道纵横比（从1.5到3.5）和三个建筑物高度轮廓（布置）基于高度的建筑物）。

该研究基于建模技术。在一年中，每种情景都分析了七个代表性的天气情况。使用考虑了OTC时空变化的特定指标来分析结果。其结果取决于盛行的低风和阴天的频繁发生。在高街道纵横比（2.5–3）和面向NS的街道上观察到了最佳的OTC水平。尽管从年度角度看，面向街道的NE-SW显示出最差的OTC性能，但与可接受范围的偏差并不高。对于特定的天气类型，街道朝向之间的差异更大。结果为高层建筑提供了充足的城市参数，以改善炎热潮湿热带地区的OTC。