狭管现象解释（Explanation of narrow tube phenomenon）.docVIP

狭管现象解释（Explanation of narrow tube phenomenon） Phenomenon prevention The wind is blocked in the air by a rugged surface, the wind narrow pipe effect The flow direction and flow velocity will also change. The tall buildings in the city, such as mechanical stirring bars, stir the wind over the city. In fact, the churning wind over the city is not a smooth flow. It is irregular and unstable, and scientists call it the turbulence. Only when the turbulence reaches a certain height, about 1000-2000 meters above the surface, can it get rid of the influence of topography and buildings, restore into a steady state of flow, and integrate into the atmosphere of the current. On the roof of the building as the boundary, from the roof to the central city called cumulus boundary layer, which belongs to the meteorological science in the mesoscale climate, the mutual influence of various thermal and wind distribution in the city life, accelerated turbulent mixing, which makes the material and energy exchange is frequent; the roof of the building to the ground below call the city covering layer, is small scale in meteorological science and climate, building density, height, shape, orientation, and the width of the street to the doors and windows, green area, the pollutant concentration in the air and many other human factors related. Small scale climate can be subdivided into building climate, urban streets, canyons, climate, business district climate, residential climate and industrial zone climate, and so on. The wind in high-rise building will change the direction of the sinking of the wind are blocked, and the floor of the channel narrows, air flow through when squeezed, when reduced to the pedestrian height will be the vortex wind, draught and angular wind flow three wind zone. The road on both sides of the level of scattered buildings comprise the street canyon, the wind often join in the street canyon, appears turbulent vortex cyclone and lifting airflow, which is commonly refe