J0504-1-4 角柱の後流物体干渉流力弾性振動([J0504-1])流体関連の騒音と振動(1))

抄録

Wind tunnel experiments are carried out to investigate the characteristics of cross flow vibration of a square cylinder with a side length d=26mm induced by setting a plate in the wake of the square cylinder. When a plate of width w=d and cross flow length l_d=2d is set with a gap ratio s/d<1.O, a large vibration occurs at U>5m/s with the maximum amplitude at around s/d=0.3. The amplitude at s/d=0.3 increases divergently with flow velocity. Measurement of the lift force on the square cylinder and the velocity in the near wake for the corresponding fixed system showed no evidence for periodic change of flow responsible for the vibration. These results show that the vibration is caused by the fluid-elastic instability but not by a periodic vortex shedding. Hence, the name "Wake Body Interference Fluid Elastic Vibration (WBIFEV)" for this vibration given in the previous paper is confirmed to be reasonable.