Development of heat environment model based on three-dimensional plume model

  • Kosuke IGARI, 2016: Development of heat environment model based on three-dimensional plume model .

Abstract


In recent years, it is the problem for aggravation of the heat environment by the urban development. It is necessary to examine effective measures in each city or area. Enforcement of the environmental impact (EIA) is one of its measures. The investigation element in the EIA can be varied, but there are not the headings about the heat environment. However, it is regarded as one of the most important themes in recent city planning and there is movement to establish it really headings. Thus, we should develop model necessary for investigation and argument in the EIA. In the field of weather and building, they develop various models about heat environment evaluation, but they are not models for using in EIA. In this study, we developed the simple model that even it is generally considered all elements about heat environment and available for EIA. The model that we used in this study was radiative estimated type, Force-Restore model and plume model. At first, we inspected each model by comparing it with observation result. Thereby, we could confirm that models can reproduce time change of radiation, the surface temperature and time change, and the temperature by that heat transports and spreads. So, we confirmed whether the change of temperature and time could express by performing the numerical experiment to evaluate influence on the heat environment of buildings and land use in the city by using the simple model built by them. As a result, we could calculate the time changes of surface temperature and sensible heat flux and also chase the time change of air temperature by it. In addition, we could express the difference in going up and down of the air temperature both the green area and the city area. About the maximum air temperature, the city area was higher 0.4℃ than the green area ,and about the minimum air temperature, the city area was lower 0.2℃ than the green area. We could confirm the influence on air temperature by the heat to the plumb direction and reproduce a proper result generally. Furthermore, by experimenting when we built one building in the domain, we also could reproduce the influence of shadow by the building, the heat storage and so on.

Keywords: city heat environment, environmental impact assessment, plume model, heat transportation diffusion