YU Chunfang1,JING Hongmiao1,2,3,WANG Yangxue1,ZHANG Jitao1,SHAO Linyuan1,LIU Qingkuan1,2, 3
JOURNAL OF VIBRATION AND SHOCK. 2024, 43(6): 216-224.
To further understanding of the influence of streamwise gust inflow on the aerodynamic forces and flow around a circular cylinder, a 3D large eddy simulation (LES) of flow over a circular cylinder with Reynolds number (Re) of 1000 was carried out to investigate the influence of streamwise sinusoidal inflow with different frequencies on the aerodynamic forces and flow field. The lift and drag coefficients, Strouhal number (St), recirculation length, separation angle and wake structure were analyzed in detail. The velocity of streamwise sinusoidal inflow was set as , where the frequency of the inflow ranged from 0 to 0.3Hz,U0 the mean velocity,A the amplitude of the inflow, A = 0.15 U0. The results indicated that dominant frequency of the drag coefficient was substantially consistent with the frequency of the inflow. There were three obvious peak values of the frequency of the lift coefficient, which were the value of vortex shedding frequency minus inflow frequency, vortex shedding frequency, and the value of vortex shedding frequency add inflow frequency, respectively. The St is reduced first and then increased, with increase of the sinusoidal inflow frequency, and the minimum value can be obtained when f = 0.25Hz, while the recirculation length is increased first and then decreased, and the maximum value can be obtained when f = 0.15Hz. The separation angle was unchanged when f <= St, and the minimum streamwise velocity gradually increased; nevertheless, the separation angle gradually increased when f > St, and the minimum streamwise velocity gradually decreased.