Effects of angle of attack on vortex induced vibration and galloping of tall buildings in smooth and turbulent boundary layer flows

摘要

Effects of angle of attack and free stream turbulence in occurrence of vortex induced vibration and galloping of tall buildings were investigated by wind tunnel experiments. From the investigation, the following results were obtained: (1) The vortex induced vibration is strengthened by free stream turbulence when the separated shear flow does not reattach to the side face. (2) The onset velocities of vortex induced vibration and the galloping vibration are the smallest and the amplitude of the vibrations are the largest when wind attacks normal to the face. (3) The critical velocity V/nBD for the level of the normalized rms displacement y/H = 1/250 is about 5 and is little affected by the side ratio where H is the height, B is the breadth and D is the depth of the building in the flow direction.