深水立管涡激振动单模态响应时频联合预报模型

Time-frequency prediction model for vortex induced vibration single-modal responses of deep water riser

利用基于圆柱体的受迫振荡试验数据提出的流体力模型,依据VIVANA的频域方法识别主导响应频率并建立升力和阻力模型,推导立管涡激振动单模态响应时频联合预报模型,在时域内通过迭代求解出立管的单模态涡激振动响应。结果表明:所推导的时频联合预报模型可用来预测立管的主导响应频率,对于低流速下激励出的单模态响应预报结果与试验结果吻合较好;对于高流速激励出的多模态参与的响应,整体响应及振型预测较好,但不能很好地预测出某些局部峰值。

Using the fluid force model based on the data from forced oscillation tests of rigid cylindrical bodies, the dominating response frequencies of the riser were identified by VIVANA frequency domain method. And a lift force model and a damping force model were obtained. And then a time-frequency model for the predication of single-model vortex induced vibration （VIV） responses of riser was established. The VIV responses of the riser were obtained by solving the partial differential equation in time domain. The results show that the dominating response frequencies can be predicted by deduced timefrequency model. And the predicted responses agree well with the experimental ones in the case of single-modal responses induced by low velocity current, and in the case of multi-modal responses induced by high velocity current, the global responses agree well with the experimental ones but some local peaks couldn＇t be well predicted.