论文标题
流体流动圆柱上涡流诱导的力的非线性模型
A nonlinear model of vortex-induced forces on an oscillating cylinder in a fluid flow
论文作者
论文摘要
提出了一个非线性模型，该模型与横向力系数相关的循环圆柱体的施加运动。针对扫荡正弦和多动力激发，研究了具有涡流脱落模式，限制周期振荡和同步的非线性流体系统。非参数非线性失真分析（FAST）用于区分奇数和即使是非线性行为。从非线性分析获得的信息明确用于构建多项式非线性状态空间（PNLSS）类型的非线性模型。与通用建模方法相比，后者导致参数数量的减少和精度增加，而通用建模方法通常不使用这种非线性信息。所获得的模型能够准确地模拟横向力系数的时间序列，这是在强加的圆柱运动的频率振幅平面上的。
A nonlinear model relating the imposed motion of a circular cylinder, submerged in a fluid flow, to the transverse force coefficient is presented. The nonlinear fluid system, featuring vortex shedding patterns, limit cycle oscillations and synchronisation, is studied both for swept sine and multisine excitation. A nonparametric nonlinear distortion analysis (FAST) is used to distinguish odd from even nonlinear behaviour. The information which is obtained from the nonlinear analysis is explicitly used in constructing a nonlinear model of the polynomial nonlinear state-space (PNLSS) type. The latter results in a reduction of the number of parameters and an increased accuracy compared to the generic modelling approach where typically no such information of the nonlinearity is used. The obtained model is able to accurately simulate time series of the transverse force coefficient over a wide range of the frequency-amplitude plane of imposed cylinder motion.
