计及附加质量系数变化效应的立管涡激振动时域响应研究

Time domain vortex-induced vibration responses of a riser in consideration of the variation effect of added mass coefficient

针对海洋立管涡激振动问题提出了一套时域预报数值方法,引入附加质量单元,能够计及附加质量系数变化效应对立管模态分析及涡激振动预报的影响。基于上述方法对均匀流工况以及线性剪切流工况下立管模型的涡激振动响应进行分析,并与相应试验结果的均方根位移及曲率、应变及位移响应时历曲线以及响应幅值谱进行了对比。结果表明,本文模型能够有效预报海洋立管涡激振动响应,且与传统数值模型相比,本文模型预报结果与试验数据更为吻合,可以较好地体现附加质量系数变化效应对涡激振动预报较为明显的影响。

A new time domain vortex-induced vibration（ VIV） prediction method for a marine riser was proposed,and a special added mass element was introduced,which can take into consideration the variation effect of added mass coefficient on modal analysis and VIV prediction. Based on a recommended prediction model,the VIV response of riser models under uniform flow and sheared flow were simulated and the predicted results were compared with the test results about the root mean square amplitude as well as the time histories and amplitude spectra of the curvature,strain and displacement responses. It is found that the new time domain model can predict VIV responses of marine risers effectively and the predicted results are much more consistent with the observed test data than that of traditional numerical models.The variation effect of added mass coefficient on VIV response can affect the predicted results evidently.