LES Study on the Influence of Streamlined Accessories on the Wind Loads of TTU Model

The high extreme negative pressure that occurs in the corner area of the roof of a low-rise building is the focus of the wind-resistant design of its envelope. Based on the aerodynamic principle and the standard building model of TTU (Texas Tech University), this paper designed a new streamlined add-on accessories in the corner area of roof according to the wind flow patterns in the roof corner. By altering parameters such as the height and length of additional components, it conducted a comparative study involving rigid model pressure measurements in wind tunnel tests under 10 working conditions and Large Eddy Simulation (LES). The study aimed to explore the impact of these new types of additional components on wind loads in roof corner zones, aerodynamic optimization for wind resistance of roofs, and the accuracy of LES simulations. The study shows that: 1) the wind tunnel test results show that the installation of add-on accessories in the roof corner area can effectively reduce the extreme negative pressure in the corner area, and the most unfavorable mean negative pressure in the roof corner area can be reduced by 10%, and the most unfavorable extreme negative pressure can be reduced by 25% under the 10 working conditions studied; 2) the NSRFG (Narrowband Synthesis Random Flow Generation) method is used to generate the inlet turbulence, and the wind load distribution pattern in the TTU model under various conditions is obtained by the LES simulation. Although the absolute value of the mean wind pressure coefficient of the roof under some working conditions simulation results are larger (the mean error is 13.88%), and the extreme wind pressure coefficient is smaller (the mean error is 9.72%), it is overall consistent with the wind tunnel test, indicating that the NSRFG method has good accuracy; 3) LES numerical simulation parameter study shows that the influence of the length of the add-on accessories on the wind load in the roof corner area is greater than that of the height, the extreme wind pressure coefficient in the roof corner area decreases by 6.15% after the height of the equal length add-on accessories increase by 1 times; the extreme wind pressure coefficient in the roof corner area decreases by 10.77% after the length of the equal height add-on accessories increase by 0.8 times.