Numerical Simulation Of Wind Field Based On Canyon Terrain

Plain topography has become more and more inadequate to meet the future needs with the rapid development of Urbanization,which will inevitably be a trend to improve planning and construction in the hilly areas.But the terrain of our country is so complex that the mountainous area of the country’s total area of about 80 % and in which about 66% of the population is living.The investigation of the speed of the winds and wind pressure in the hilly areas is significantly affected due to complex landform and diversified structure of the hilly areas.Also planning and construction in the hilly areas is affected by severval major aspects like the basic characteristics of the hilly areas,vegetation rate,building height and spacing,etc.In the present study at home and aboard,the simple model of the hilly areas is focused on the influence of flow field characteristics.since the complex landform of hilly areas and vegetation rate lacks intensive study,the study of architectural composition is only an model for a building instead of the composition of hilly areas.so it is very purposeful to investigate vegetation rate and architectural composition on complex landforms due to poor reference in the practical project.In this paper,Numerical analysis was used to be the major method,which numerical simulation can be obtaind with ICEM and fluent.data analysis is finished by tecplot and origin.Realizable k-? turbulence model is used to count the influence of vegetation rate on the speed of the winds in the hilly areas and the influence of building height and spacing on the complex landforms on wind ambience.In this paper,the landform of haungxian village will be the research object.The main reseach contents are as follows:1.To reconstruct a three-dimensional model of ravine base on DEM data.Numerical simulation is studied by different turbulance models,and compare to practical data.it has been found that Realizable k-εturbulance model is quite reasonable.2.The influence of slope gradient and surface roughness of different landformson speed of the winds is studied in simple two-dimensional or three-dimensional terrains,which surface roughness indicates vegetation rate.And compare the influence of surface roughness in complex landforms on the speed of winds with the practical data.it can be found that the value of the speed of winds on windward side and leeward side in Class A and Class B decreases with the value of surface roughness increases when slope gradient is 0.2,0.4,0.5,0.8,1.0.while the value of the speed of winds on windward side and leeward side in Class C and Class D increases with the value of surface roughness increases,but the range of variation is small.The vertex in four landforms decreases with the value of the surface roughness increases.The variation of the speed of winds is comparatively large,about 10%,when the slope gradien is 0.8 and 1.0 only in Class C landforms.While in Class B the speed of winds decreases with the value of surface roughness and the variation is not large.3.choose the better place with good comfort according to the criteria evaluation of the value of the speed of winds and wind velocity ratio.The simulation study of building height and spacing in planning and construction in the hilly areas is conducted and analyse the influence of height and spacing on wind ambience.then propose some advices that is corresponding.It come to a conclusion that the palces when the value of the speed of winds and wind velocity ratio is relatively large is livable;aggrandizement of height in a certain range in low rise building leads to better wind ambience and the environment quality of wind ambience in the downstream of air flow improves when the spacing increases.