【作者】 罗敏；

【导师】 刘巨保；

【作者基本信息】 大庆石油学院 ， 化工过程机械， 2009， 博士

【摘要】 管道内旋转细长梁是化工机械、石油钻采工程中的特有结构,开展旋转细长梁固液耦合动力学分析方法研究,对细长梁结构优化设计、工艺参数优选等技术发展具有重要意义。旋转细长梁与不同环空间隙的管道内壁产生多向碰撞接触,同时空心旋转细长梁内部以及外部环空有流体作用,构成一个复杂的非线性固液耦合系统。因此,本文首先采用动力间隙元和空间梁单元、Newmark积分法,对管道内旋转细长梁进行碰撞接触动力学分析计算,得到时间步长、积分常数等参数对细长梁动力学分析结果的影响。其次,建立了不同偏心情况下环空流体力学分析的三维数值模型,揭示了偏心环空流体流动特性及界面力随转速和偏心度的变化规律;在偏心度大于0.8时,轴向等截面偏心环空螺旋流的界面力能阻止其偏心。然后,设计和建立了管道内旋转细长梁固液耦合模拟实验装置,实验研究了转速和流量对旋转细长梁运动状态的影响规律,以及旋转细长梁与管内外螺旋流体的固液耦合效果。最后将旋转细长梁沿轴线离散为若干个梁单元,管道和环空流体分别离散为若干个等长度的三维管道流体段和任意偏心环空流体段,每个流体段又被离散为四面体或六面体网格,建立了管道内旋转细长梁固液耦合动力学分析的三维数值模型;将结构动力学方程、流体连续方程和动量方程耦合,推导了界面力、界面位移的计算公式、迭代格式及收敛准则,建立了管道内旋转细长梁固液耦合动力学分析方法。为了解决管道和环空螺旋流体离散单元多、PC机无法计算的问题,提出了管道和环空流体特性描述数据库,该数据库能够自动记录和提取不同流体段、不同工艺参数下的流体分析结果;根据上述模型和理论,编制了管道内旋转细长梁固液耦合动力学计算程序,通过算例表明了固液耦合效果,且数值计算结果与实验结果基本吻合,验证了固液耦合理论方法的正确性。本文研究成果可为化工机械中的细长旋转轴和搅拌轴、石油钻采工程中的抽油杆柱和钻柱的固液耦合分析提供了理论基础和计算方法。更多还原

【Abstract】 The rotary slender beam in pipe is the peculiar structure in the chemical engineering machinery and oil drilling and production engineering. The research of the rotary slender beam fluid-structure interaction dynamics analysis was presented the theoretical significance and application for the structure optimized design and the optimization of the process parameters. The rotary slender beam is collision with the pipe inner wall about different annular clearance. The rotary slender beam also has fluid interaction in its inside and outer annular. It forms a complex nonlinear fluid-structure interaction system. First, the dynamic gap element, three-dimensional beam element and Newmark integral method is adopted. The rotary slender beam in pipe is proceeded collision and contact dynamical analysis. The impact is obtained about the parameters of the time step and the integral constant to the result of the dynamical analysis. Second, the three-dimensional fluid dynamics analysis model is established with different eccenters. It is revealed that the variable rule about the eccentric annulus fluid flow characteristics and interfacial force with the speed and eccentricity. If the eccentricity is greater than 0.8, the interfacial force about the axial uniform cross section eccentric annulus helical flow can prevent the eccenter. Third, The experimental simulation apparatus is designed and established about the rotary slender beam fluid-structure interaction system. It is studied the variable rule of the impact about the flow rotate speed and the flow rate to the movement condition, and. the fluid-structure interaction effect of rotary slender beam and helical flow inside and outer of pipe. Finally, The rotary slender beam is scattered to several beam elements along axial line. The hydraulic pipelines is scattered to several equal long three-dimensional hydraulic pipelines fragment. The annular flow is scattered to random eccentric annular flow fragment. Every fluid fragment is also scattered to tetrahedron and hexahedron grid. The three-dimensional numerical model is established about the fluid-structure interaction dynamic analysis of rotary slender beam in pipe. The equations of the structure dynamics, fluid equation of continuity and momentum equation are coupled. The calculation formula about the interface force and displacement with eccentricity and eccentric angle are derived. The congruent iterative format and convergence criterion are also derived. The method about the fluid-structure interaction dynamic analysis is proposed. In order to solve the problem great quantity element number of the hydraulic pipelines and annular flow and the disability of the PC machine, the characterization database about the hydraulic pipelines and the annular flow is established. The database is able to automatic record and extract the fluid analysis result of different flow fragment and different technological parameters. Based on the above models and theories, the computer program is compiled about the fluid-structure interaction dynamic analysis of rotary slender beam in pipe. The fluid-structure interaction effect was showed by example. The fluid-structure interaction numerical arithmetic result was fundamental coincided with the experimental result. It was verified that the validity of the fluid-structure interaction theoretical method. The results of research in this article would provide a theoretical and arithmetic method for the fluid-structure interaction analysis of the rotary slender shaft, the stirring shaft in the chemical engineering machinery and the rod string and drill string in the oil drilling and production engineering.更多还原