Xu Ming presents iUHIST, a simulation tool that models how urban design affects heat in Singapore. The tool was tested on the National University of Singapore's Cantwell housing facility to measure whether design strategies actually cool neighborhoods.
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Urban heat island effect is the phenomena that the air temperature in urban area is relatively higher than the rural area. Mitigate urban heat island effect and improve urban thermal environment will enhance the livability of a tropical city like Singapore. While urban designers and architects need tools to quantify the impacts of their design strategies on urban thermal environment, which is the initial momentum Develop this Integrated Urban Heat Island Simulation Tool.
Hello, I'm Xu Ming and doing numerical modeling for Kudakama Singapore Impact project, I developed the integrated urban heat island simulation tool by accounting for major heat sources and sinks in Singapore context. Major heat sources include solar radiation and anthropogenic heat such as waste heat from building, energy consumption, traffic and industrial activities. Major heat sinks are greenery and water bodies. This tool is developed by coupling conjugate heat transfer with the normal computational fluid dynamics. A typical computational fluid dynamics model could simulate the air pressure and airspeed which can be used to calculate drags around moving bodies such as those around a motorcyclist. Heat is transferred in forms of heat conduction, convection and radiation. With numerical modeling of conjugated heat transfer, we could simulate phenomena such as the air temperature distribution pattern in a closed room where there is a heater in a corner, or the temperature distribution pattern of both air and water which are heated up by a heater in the middle even with an adiabatic solid on the left of the heater, or the air temperature and humidity profile of a car cabinet when the driver starts the engine in a cold and humid winter morning, or a fan blowing hot air passing through the porous media. These simple results are the theoretical foundations of the tool.
A case study of Cantwell is carried out to illustrate the tool capabilities. Cantwell is the housing facility of National University of Singapore for its faculty members. By including major heat sources and sinks in the model domain of Cantwell buildings, ventilation is first simulated around the buildings and then solar radiation and air temperature on a typical day of each month is validated against the observed data. The comparison results show the performance of the developed tool is quite good. The tool could be applied to evaluate the impacts of design strategies on urban thermal environment. For instance, if we change the facade shape from straight to curved to mimic that of the Marina Bay sands, we could see its impacts on surrounding air temperature. Unfortunately, such a curved facade does not help to cool down the surrounding air, if not making the situation even worse. This study summarizes the development process of the integrated open heat island simulation tool with the case study of Cantwell. It shows that this tool can be implemented to identify the contributions of each heat source and see think carry out sensitivity analysis. And of course, to evaluate the impact of design strategies on urban thermal environment.
