水击流固耦合的判断准则探索

水击理论在进行水击计算时忽略管道结构的动态特性对水击压力的影响。这种忽略对于受很大约束的管道系统的水击计算是可行。但对于实际应用中最大量使用的弱约束管道系统，管道结构的运动和变形可能会对水击压力产生很大的影响。根据管道结构的运动和变形对水击压力的影响进行了研究，阐明了管道有压流系统中流体-结构相互作用的机理，论述了摩擦耦合、泊板耦合，接合部耦合和泊松接合部耦合4种形式，通过典型算例分别研究了管道的轴向运动、弯曲和扭转对水击压力的影响。发现轴向运动对水击压力的影响最大，而管道的弯曲和扭转对水击压力的影响较小。

A guideline on the importance of water hammer FSI

The effect of pipe structure dynamic behaviors on water hammer is neglected in classical water hammer theory.Such neglecting is valid for the pipe systems with strong restrictions.As for the infirmly restricted pipe systems widely employed in practice,the motion and distortion of the pipe may obviously impact on water hammer.Such influence is thoroughly investigated in this thesis.The author illustrates the mechanism of the fluid and structure interaction(FSI),describing the four types of coupling:friction coupling,possion coupling,junction coupling and possion junction coupling.By applying the MOC to the typical examples,the author researches the influence of pipe axial motion,bend and torsion on water hammer separately,and discovers that the pipe axial motion is dominative and the effect of bend and torsion on water hammer is very slight.After summarizing the calculating results,a guideline is concluded,which can judge when FSI is important.