Study on Atmospheric Environment Around River

点击翻译按钮获取中文摘要

The cooling effect of river on atmospheric temperature around rever in summer is a well known phenomenon in qualitative respect, but not in a quantitative respect. To evaluate quantitatively, the physical model describing the transport process of momentum and heat is necessary. For construction of the model, wind velocity, temperature and humidity were observed around River Watarase and River Kyuryu. The temperature of river side was 2-3 ﾟC lower to compared to urban area. The turblence thermal diffusion coefficient of vertical direction was order of 10^<-1> m^2/sec. In addition to observations described above, some experiments were carried out in wind tunnel having 90x90 cm cross section. A river channel is simulated by a long square pipe (12.5x8 cm cross section), and dry ice was set inside of this pipe as cooling source. Both side of this pipe, heat insulating material covered with artificial lawn as surface roughness were installed as river side area. Wind velocity was measured with 2- dimensional hot-film anemometer. Change of value of Reynolds stress and eddy viscosity, and of their profiles were analyzed in combination with experimental conditions of cooling and wind velocity.