EFFECT OF CURVED SHAPE BALCONY ON MEAN WIND PRESSURE COEFFICIENT VALUES OF HIGH RISE BUILDINGS USING CFD SIMULATION

Abstract

Wind pressures on buildings are influenced by a variety of factors such as balconies and the overall roughness of the building envelope. The influence of the building envelope configuration on the wind loads on cladding and structural parts of a building must be determined in order to identify any alterations required for wind codes of practice and design standards .Four wind directions are chosen θ=00, θ=450, θ=900 and θ=1800 to see the effect of this roughness, which is placed at one façade or side of the building on terrain category-2. The study's fundamental model consisted of square buildings with opening in four directions with height of 120m, that contain 2m and 4m wide curved balconies, 4m wide curved balconies with vertical wall at the middle ,and 4m wide curved balcony with 1m and 2m height parapet wall, which is mainly based on steady Reynolds averaged Navier-Stokes (RANS) approach. The evaluation is based on validation with wind tunnel measurements of normalized mean wind velocity and longitudinal turbulence intensity of Stathopoulos and Zhu (1988). For 00 wind directions, the presence of appurtenance (balcony) increases the positive Cp,mean pressure value. For oblique or 450 wind direction, also reduces the positive Cp,mean value by 48.6% . For 900 wind directions, 2m width balcony with no parapet, 4m width of balcony with no parapet wall and 4m width, 2m height of parapet wall and 30.4 m width of balcony at the middle of the building increases the positive Cp,mean value. For 1800 wind directions, when we see the negative Cp,mean value other than 2m width of balcony with no parapet wall, which reduces the Cp,mean value by 1% the rest increases Cp,mean value. When we compare buildings with a rectangular and curved shape a 2m width of curved balcony with no parapet wall has more positive or pressure Cp,mean value (67%) and less negative or suction Cp,mean value (76.8%) than a 2m width of rectangular balcony with no parapet wall and the square building has higher positive Cp,mean value and lower negative Cp,mean value than a rectangular building. Regarding with the codes and standards, the width of curved balcony creates more pressure or positive Cp,mean value and more suction or negative Cp,mean value than both the EBCS and IS codes.