Vibration Characteristics of Different Cross-Section Pipes With Different End Conditions

Abstract

This paper investigates the effect of end conditions on the vibration characteristicsof a pipe conveying fluid with different cross sections such as (sudden enlargementand sudden contraction). The governing equation of motion for this system is derivedby using beam theory. Three types of end pipe supports (flexible, simply and rigid)were adopted to investigate their effects on the vibration characteristics. Also, theeffect of some design parameters like pipe diameter, length, pipe material, and theeffect of fluid velocity were investigated.Two different pipe systems of different diameters were investigated, model-1[12.7mm, 25.4mm, 12.7mm] and model-2 [6.35mm, 12.7mm, 6.35mm] with length[0.25m, 0.5m, 0.25m] and model-3 with same diameter for model-1 but with length[0.5m, 0.5m, 0.5m]. Three pipe materials were tried, copper, steel and aluminum. Theeffect of Reynolds number between (500 - 1500) was also investigated. The dynamicbehavior of a pipe conveying fluid is described by means of transfer matrix method. AMatlab- R2007 language computer program has been developed in this study to predictthe vibration response.The results of Matlab program were compared with those from ANSYS-11program and it is found that there is a good agreement between them.