Abstract 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.

中文翻译：

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流体流动中振荡圆柱体上涡致力的非线性模型

摘要 提出了一个将浸没在流体流中的圆柱体的外加运动与横向力系数相关联的非线性模型。非线性流体系统具有涡旋脱落模式、极限循环振荡和同步，针对扫频正弦和多正弦激励进行了研究。非参数非线性失真分析 (FAST) 用于区分奇偶非线性行为。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。与通常不使用此类非线性信息的通用建模方法相比，后者导致参数数量的减少和准确性的提高。