波流联合作用下隔水套管的涡激非线性振动

考虑流及波流联合作用,研究了套管的涡激非线性振动.将套管简化为梁模型,计及莫里森非线性流体动力和涡激荷载,建立套管的涡激振动方程.采用克雷洛夫函数求解套管的固有频率和模态,提出了计算涡激非线性动力响应的迦辽金方法.以东海勘探3号钻井隔水套管为例,研究了流引起的主共振和波流联合引起的组合共振.计算结果表明:流对套管的动力响应占主导地位,而波的影响不大.分析了前四阶模态、升力系数、流体阻尼系数对套管动力响应的影响.揭示了波流联合激励下套管复杂的动力响应特性.

Vortex Nonlinear Vibration of Marine Risers in Waves and Current

The vortex-induced nonlinear vibration of marine risers in deep water is studied considering the loads of current and combined wave current.The vortex induced vibration equation of marine risers is set up with considering the beam mode and Morison's nonlinear fluid damp as well as the vortex-excited loads.The approach of calculating vortex-excited nonlinear vibration by Galerkin's method is proposed.The responses including primary resonance induced by current and the composite resonance under combined wave-current for the marine drilling risers of the Donghai 3 are studied.The numerical results show that the dynamic response of marine risers induced by the current takes the main status and the influence of wave may be neglected.The contribution of the first four modes,lift coefficient,the damping coefficient of fluid to the dynamic response of marine risers is investigated.The complicated response behaviors of marine risers are described under combined wave-current based on the numerical simulations.