考虑垂直湍流和水平流动热交换的空气温度计算模型

Calculation Model of Air Temperature Considering Heat Exchange Due to Vertical Turbulence and Horizontal Air Flow

为了解决城市区域近地层空气温度的计算问题,将近地层空气在垂直方向上划分为若干层,针对每一层空气建立能量平衡方程,在方程中考虑了垂直方向上的湍流热交换作用和水平方向上的来流空气热交换作用,通过与下垫面和建筑墙面能量方程的联合求解可以得到近地层空气温度的垂直分布.采用广州地区小尺度区域(水平范围小于500m)和大尺度区域(水平范围大于1000m)夏季的测试结果对模型计算结果进行验证.结果表明,模型计算结果与测试结果比较接近,小尺度区域比较样本中最大相对误差为4.18%,说明该模型在预测城市区域近地层空气温度方面具有一定的准确性,可以用于城市热岛和热环境的理论分析.

In order to calculate the air temperature of the near surface layer in urban environment, the surface layer air was divided into several layers in the vertical direction, and some energy balance equations were developed for each air layer, in which the heat exchange due to vertical turbulence and horizontal air flow was taken into account. Then, the vertical temperature distribution of the surface layer air was obtained through the coupled calculation using the energy balance equations of underlying surfaces and building walls. Moreover, the measured air temperatures in a small area （with a horizontal scale of less than 500m） and a large area （with a horizontal scale of more than 1000m） in Guangzhou in summer were used to validate the proposed model. The calculated results accord well with the measured ones, with a maximum relative error of 4. 18% in a small area. It is thus concluded that the proposed model is a high-accuracy method to theoretically analyze the urban heat island and the thermal environment.