Numerical study on aeroelastic behavior of spoiler on low-rise building based on fluid-structure interaction method

Abstract

Technical mitigation devices have been demonstrated to be efficient for decreasing the peak and mean wind pressures on the roof systems of low-rise buildings through disrupting vortex formation. Previous investigations have regarded mitigation devices as rigid bodies and neglected aeroelastic behavior. However, the relatively large uplift force induces small-stiffness mitigation devices vibration and introduces a considerable aeroelastic effect. These effects might result in an increase in negative wind pressure on the building roof and the aeroelastic instability problems of mitigation devices. Therefore, the current study conducted two-way fluid-structure interaction (FSI) numerical simulation for a low-rise flat-roof building with mitigation devices (metal and polymer spoilers) to investigate the influence of the aeroelastic effect of spoiler on the wind pressure on the building roof. The large eddy simulation (LES) method and the finite element analysis (FEA) model are used to solve the flow field and the structural responses of the spoiler, respectively. The computational model and method are verified by comparing the calculation results with previous experimental results and benchmark computational tests. The dynamic response of spoiler, the flow instabilities and the wind pressure on the building roof are analyzed. The influence mechanism of the spoiler vibration on the flow field over the building, the wind pressure on the building roof and the uplift force on the spoiler were revealed considering the influencing factors, including the vibrational amplitude of spoiler and the wind direction. The results show that the aeroelastic effect of spoiler increases the negative wind pressure on the roof, and the larger the vibrational amplitude of spoiler is, the more the negative wind pressure increases. The negative wind pressure on the eave also increases with increasing wind direction angle. The main reason for this phenomenon is that the spoiler vibration increases the degree of flow separation over the building roof.