装配式管线水力瞬变的非线性流固耦合模型

装配式管线是一种重要的油料保障装备,用于地面铺设,属于典型的薄壁弱约束管线系统。根据装配式管线的特点,应用管道弹性变形理论,推导了水力瞬变状态下装配式管线的非线性流固耦合5-方程模型。该模型充分考虑了管道与流体之间的耦合互动效应,耦合形式包含了泊松耦合、摩擦耦合、结合部耦合,以及管线系统的轴向、横向和径向振动耦合,并计及了管道结构阻尼的影响。针对装配式管线的特殊连接约束方式,提出了一种带有扭转弹簧的铰支型约束边界,可通过确定扭转弹簧的弹性系数来建立管线两端的约束边界方程。

The Nonlinear Fluid-structure Interaction Mathematical Model for Hydraulic Transient of the Assembled Pipelines

The assembled pipeline, a typical thin-wall weak-restriction pipeline, is very important oil support equipment, which is laid on the ground. Considering the characteristics of the assembled pipeline, a 5-equation nonlinear fluid-structure interac- tion model for the assembled pipeline in hydraulic transient state is developed according to the elastic deformation theory of pipe- lines. In this proposed mathematical model, the coupling effects are taken into the full consideration and the concrete coupling forms include poisson-couplings, friction-couplings ,junction-couplings and axial, lateral, radial oscillation couplings of pipeline sys- tem. In addition, the structure damp effects of pipeline are introduced too. In order to simulate the special connected restriction mode of the assembled pipeline, a hinged support restriction boundary with torsional spring is put forward. By confirming flexibility quotiety of torsional spring, the equation of restriction boundary on each end of pipline can be built.