Dynamics Analysis Of Viscoelastic Fluid-conveying Pipeline Analysis In The Supercritical Regime

Fluid-structure coupled vibration of pipes conveying fluid system at present in varietiesof industrial applications, and the research results has been widely applied in various fieldson submarine oil manifold engineering, hydropower engineering, aerospace engineering,nuclear engineering and biological engineering, and so on. Have great theoretical researchvalue and realistic significance.For pipe diameter to length ratio less than1/10slender straight pipe,if the flow speed islarger than the critical value, pipes conveying fluid becomes unstable,and the system will bestable in the curve equilibrium configuration.In this study, the post-buckling configurationsdifferential equation of fluid-conveying pipes supported at both ends is investigated based onthe nonlinear equation governing the transverse vibration Kelvin viscoelastic pipes. Theexpression of buckling configurations for hinged-hinged pipe conveying fluid is obtained. It isfound that the fluid flow speed exceeds the critical value, the straight equilibriumconfiguration becomes unstable and buckling deformation occurs. For the governing equationin the supercritical state, by using Galerkin method, we found that the partial differentialequation is reduced to ordinary differential equation. Then, the first supercritical naturalfrequencies for pined-pined case is obtained analytically.By using Galerkin method, we established that the partial differential equation is reducedto ordinary differential equation with cubic and square.Then, both the weakly and stronglynonlinear vibration is solved by using homotopy analysis method (HAM) and the solution isexamined by numerical results.Considering the viscosity of real fluid cause of the non-uniform of the fluid flow speeddistribution in a fluid-conveying pipes.In the cases of laminar flow and turbulent flow,thepost-buckling configurations differential equation of motion of the supercritical pipeconveying fluid is modified. The non-uniform distribution of flow velocity under differentconditions of supercritical flow pipeline buckling configuration changes,and ideal fluid undersupercritical flow pipeline were compared In the end, study the propagation characteristics influence for the flow viscosity incondition of the fluctuation and in a pipe conveying fluid with an infinite length. Based on thenonlocal elastic constitutive relation, the wave equation of flow pipeline isdeduced.Numerical simulation in the case of different coefficient of viscous fluid effects onwave flow pipeline.