BCM-LES for moving cIBM on aeroelastic stability of a tall building with various modes

This study analysed the mechanism of unsteady negative pressure around a square cylinder during forced oscillation in the rocking or the first order beam-bending mode, using an advanced large eddy simulation solver on the hierarchical Cartesian grid system using the constraint immersed boundary method for arbitrary moving boundary shape. The study also investigated an onset of negative damping force in relation to the reduced velocity and the oscillation amplitude. The results showed that in the beam-bending mode, the phase of pressure generally advanced more for the reduced velocity defined by the cylinder width, wind velocity and oscillation frequency compared to that of the rocking mode, and the transition to negative damping force occurring at a lower reduced velocity. The findings also indicate that the generation of negative pressure was influenced by timing and location of the vortex formation in the wake of 3D square cylinder.