摘要
对二维平面均匀剪切流作用下,弹性支撑圆柱体在横向和流向运动的涡激振动进行了数值模拟.数值计算实现了雷诺数在[2000,5000]内,圆柱体在不同剪切率[0.01,0.05]条件下的涡激振动.圆柱体的横向振幅、运动轨迹、振动频率和升力系数及位移时历曲线的计算结果表明,对于不同的雷诺数,存在剪切率的"锁定区间".雷诺数较小时,剪切率的锁定区间较小,随着雷诺数的增加,剪切率的锁定区间增大.在剪切率的锁定区间内,横向振幅增大,脱离剪切率锁定区间后,横向振幅迅速下降.计算结果发现圆柱体的运动轨迹可以完全不同于普遍认可的"8"形轨迹,在剪切率锁定区间内圆柱体运动轨迹似"小雨点"的外形,这是在平面横向剪切流条件下得到的圆柱体运动的新轨迹.
A numerical simulation of an elastically supported cylinder in 2-D uniform planar shear flow was conducted. It simulated the vortex-induced vibrations of a cylinder with Reynolds numbers ranging from 2 000 to 5 000 and shear rates ranging from 0. 01 to 0. 05. Numerical results, including transverse amplitudes, motion trajectories, vibration frequencies, and displacements show that there exists a shear rate lock-in range with respect to various Reynolds numbers. The shear rate lock-in range is relatively narrow when the Reynolds number is small, but it soars rapidly as the Reynolds number increases. Transverse amplitude increases when shear rate falls into the lock-in range and decreases sharply when shear rate is out of lock-in range. It is also found that the vibrating trace of the cylinder in a uniform planar shear flow is completely different from the ＂8＂ shape which was commonly known. We find that this new vibrating trace resembles a raindrop within the shear rate lock-in range.
出处
《哈尔滨工程大学学报》
EI
CAS
CSCD
北大核心
2007年第12期1301-1306,共6页
Journal of Harbin Engineering University
基金
国家自然科学基金资助项目(50323004)
上海市科委专项基金资助项目(05DJ14001)
