Effect the Linear Spring Stiffness on The Stability and Dynamic Analysis of Curved Pipe Conveying Fluid

The dynamic stability of curved pipe conveying fluid occurs when the flow velocity is exceed a specific value for that the instability of system became clear. Several effective parameter play an important role in dynamic and stability of the curved pipe conveying fluid such as stiffness addition. In this research The dynamic analysis of curved pipe stiffness by linear spring for fixed-fixed ends conveying fluid consisting from several of straight pipe elements is investigated by using three dimensional finite element model. Effect of stiffness linear spring (addition),effect of spring location and flow velocity on the dynamic curved pipe was deeply studied. The characteristic matrices consisting of stiffness, inertia, damping and contradictory terms which derived by finite element method and the effect of the internal flow velocity, axial force, Coriolis force and force of spring stiffener in connected elbow are considered. The results obtained the system loss stability when the flow velocity has critical value and the dynamic behavior become very sensitive for critical spring constant. Also, the frequency of curved pipe system has best result for specific spring location. The results are compared with the numerical approach and gives good agreement of used technique. Keywords: curved pipe conveying fluid, Stability, Dynamic analysis, spring addition, critical velocity, Coriolis force