Abstract：In order to study the effect of different gap ratio L/D on the vortex-induced vibration cha-racteristics of a single cylinder and square cylinder near the wall, and to understand the mechanism of wake flow on the wall instability. An open circulating water tank experimental test rig was built, and two near-wall models under transition flow were experimentally studied by using Particle Image Velocimetry(PIV)system. The results show that they have similar vortex-induced vibration characteristics: When L/D is very small, the development of shear layer under blunt body is suppressed; as L/D increases, the suppression effect of the wall is weakened, and there is a tendency to form vortex pairs in the wake. The vortex gradually approaches blunt body and tends to be symmetric; As L/D increases, the acceleration effect of the fluid near the wall first increases and then decreases and there was a ten-dency to form vortex pairs at the wake. The vortex gradually approaches the blunt body and tends to be symmetrical. The scale of the vortex first increases and then decreases, the acceleration effect of the fluid near the wall first increases and then decreases, and the main vibration frequency gradually decreases; Both show periodic vortex shedding motion. There are also differences between them: The wake separation point of square cylinder is fixed, while the single cylinder is not; At the same Re, the scale of square cylinder vortex under the same L/D is larger than that of cylinder, and the velocity near the wall is also faster; As L/D increases, the amplitude of the wake of cylinder first increases and then decreases, while square cylinder keeps increasing and the main vibration frequency is slightly smaller, which indicating that the vortex shedding period of near the wall of square cylinder is longer than that of single cylinder. The above research results has certain reference value for practical engineering applications.
翟少华,谢福兴,尹广洲,喜冠南*. 间隙比对近壁不同钝体涡激振动特性的影响[J]. 排灌机械工程学报, 2021, 39(11): 1132-1138.
ZHAI Shaohua,XIE Fuxing,YIN Guangzhou,XI Guannan*. Effect of gap ratio on vortex-induced vibration characteristics of different blunt bodies near-wall. Journal of Drainage and Irrigation Machinery Engin, 2021, 39(11): 1132-1138.
