摘要
为了削弱涡激振动对结构的疲劳破坏作用,采用一种柱体直径沿展向非均匀变化的几何扰动作为减振或抑制措施。通过直接数值模拟,研究低Re数(100)下gf入几何扰动后具有圆形截面柱体的水动力载荷及其变化的特征.引入的几何扰动分别为谐波型和圆锥型两种。计算的无量纲扰动波长为4,6和8;扰动强度(扰动波高与扰动波长之比)分别为0.0125,0.025,0.05,0.1和0.2。计算结果表明,引入扰动后,相比引入扰动前的直柱体,两种扰动型式下的平均阻力系数均显著增大,而脉动升力系数在特定扰动波长时则显著减小。此外,水动力载荷系数都出现特定扰动范围(如扰动波长或扰动强度)下极小值现象,从而为后期设计提供优化依据。
To weaken the vortex-induced vibrations （VIV） resulting in the structural fatigue damage, a method in reducing or suppressing VIV is applied in present paper by introducing geometric disturbance, varied non-uniformly along the span, to the outer diameter of a cylinder. Through the numerical simulations, characteristics of hydrodynamic load on the circular cylinder with such disturbances are obtained. Two kinds of introduced disturbances are harmonic one and conic one, respectively. The non-dimensional wavelength of disturbance of 4, 6 and 8 are computed. The wavy steepness, the ratio of the wave height to the wavelength, of 0,0125, 0.025, 0.05, 0.1 and 0.2 are considered. The numerical results show that mean drag coefficients of the disturbed cylinders are greater than that of straight cylinder, but the RMS lift coefficients are reduced at certain wavelength. Besides, the region of the minimum of these hydrodynamic load coefficients are found in certain disturbances with specific wavelength or wavy steepness, as a way in optimization in future design.
出处
《中国造船》
EI
CSCD
北大核心
2012年第A02期205-210,共6页
Shipbuilding of China
关键词
几何扰动
圆柱
涡激振动
水动力载荷
： geometric disturbance
circular cylinder
vortex-induced vibration
hydrodynamic load
