Experimental Study In Wind Tunnel On The Effect Of The Aerodynamic Parameters Influenced By Non-Uniform Buildings

Urbanization is the world's most common social development momentum, the non-uniform of buildings is the city's fundamental structure, the role they play in atmospheric movement is a major factor in forming urban climate. This paper built a morphological parametric program which could express the non-uniform of buildings, and finished a wind tunnel experiment which is designed based on the quadratic regression orthogonal rotating combination design, and this program did a preliminary study of wind tunnel experiments on the morphological parameters.This paper discussed the Multi-layer Dynamic Urban Canopy model, which is based on optimized the existing Urban Canopy Model. As for the lack of systematic studies of buildings non-uniform and most of them were qualitative research, based on architectural geometry morphological, this paper built a morphological parame-tric method describing the non-uniform of buildings, forming a set of parameters scheme, which systematically describe buildings frontal area, density, shape, layout, wind direction, height and so on, including the frontal area index (λf), density index (λp), shape index (SBC) and integrated non-linear coefficient (R) four parameters, and this paper also gives calculation method respectively.To study the relationship between the aerodynamic characteristics and para-meters of non-uniform buildings, which based on existed morphological parameters scheme, this subject designs wind tunnel experiment by using the quadratic regres-sion orthogonal rotating combination design, taking the parameters as experimental factors. With the most accurate design of experiment, this paper focus on the inte-raction in various parameters and its effects on aerodynamic characteristics, and accurately studies the mechanism of building morphologic parameters'effects on aerodynamic characteristics.After the design of wind tunnel experiment by using the quadratic regression orthogonal rotating combination design, this paper finished the wind tunnel expe-riment, which focus on the performance of morphological parameters and other ef-fects. Through the experiment, the change of surrounding environment landscape roughness has little effect on drag coefficient. The frontal area index is the key to cause drag coefficient change by wind direction change. The distribution of wind pressure difference on the model surface has general rules, its minimum and maxi-mum mostly appears at 0.5H above model surface. The monomer drag coefficient of building on a bigger zones has the same variation trend along wind direction ap-proximation for a attenuation curve and the same fitting formula. The average drag coefficient base on pressure measurement is 10%~20% bigger than the drag coeffi-cient base on direct measurement. After contrasting the researches of these experi-ments, the frontal area index increasing, density index increasing, shape index in-creasing and integrated non-linear coefficient decreasing, the drag coefficient in-crease respectively.