# Wind Pressure Coefficient on a Multi-Storey Building with External Shading Louvers  
[PERSON]  
1 College of Mechanical and Energy Engineering, Jimei University, Xiamen 361021, China;  
[PERSON]_j_jregions with sufficient wind energy, natural ventilation between openings of building surfaces has become a common method of cooling. Wind environment is sensible to many factors, such as wind direction, building structures and surrounding conditions [16; 17]. As a common type of building component, external shading louvers can affect airflow patterns around buildings. Figure 1 shows an array of shading louvers and the control system to rotate louvers. When the rotation angle of louvers changes, it can affect the wind speed and incident angle, resulting in fluctuations in natural ventilation around the shaded building. The presence of shading louvers must be considered in wind pressure investigation. Wind-induced physical fields are investigated based on four methods, including theoretical analysis, in-situ field measurement, wind tunnel experiment and computational fluid dynamics (CFD) technology. In-situ field measurement of full-scale buildings investigates wind fields under real conditions, where all building surroundings are taken into account [18; 19; 20; 21; 22; 23]. Wind tunnel experiments, with reduced-scale models, can provide data under controlled laboratory conditions. In addition, wind tunnels have advantages for investigating specific parameters, such as wind direction and turbulent intensity [24; 25; 26; 27]. Theoretical analysis methods, based on fluid mechanisms, aim to develop analytical solutions with mathematical formulations [28; 29; 30; 25]. Numerical simulation methods, based on CFD, are used to simulate both full-scale and reduced-scale wind environment to obtain a wider range of data [31; 32]. To evaluate the nature ventilation around buildings, various parameters related to wind environments were investigated [24; 26; 28; 33; 34; 35; 36; 37; 38]. As a dimension-less parameter, the wind pressure coefficient is almost unaffected by wind speed [24; 37]. In the orifice equation, based on the sealed body assumption, the difference of wind pressure coefficient is an input to calculate the cross-ventilation capacity of the building with openings like windows and doors [13; 14; 15]. Generally speaking, the potential cross-ventilation capacity becomes higher with the larger difference of wind pressure coefficient between two outside surfaces. When openings are installed on outside surfaces of a sealed building, the pressure difference can be applied to forecast wind-induced distributions, design airflow routes and evaluate natural ventilation patterns in different wind environments. For these reasons, analyzing the distribution of wind pressure coefficient on shaded building facades is critical to exploring their potential ventilation capacity. The distribution of wind pressure coefficient is sensitive to building structure and envelopes. A parametrical model of calculating wind pressure coefficient was developed to investigate wind profile on building envelope by [PERSON] [28]. [PERSON] et al. [26] compared the pressure distributions on cube, U-shaped and L-shaped building models, which demonstrated the shading effect by building geometry. [PERSON] et al. [24] investigated the wind pressure coefficients around enclosed and open-window buildings. [PERSON] et al. [33] compared wind pressure coefficient  
Figure 1: Control system of shading louvers. data from different sources and concluded that the degree of exposure/sheltering was one of the most significant parameters causing the differences in wind pressure coefficients. Many studies evaluated the mean and local wind pressure coefficients on building surfaces [23; 25; 28; 30; 31; 33; 37; 38; 39; 40; 41; 42]. For airflow calculation models, the average values of wind pressure coefficients on each whole building surface are not sufficient, because local values at many positions have obvious deviations compared with averaged value of a whole facade [33; 43].