دراسة تأثير الفيض الحراري في الاهتزاز الناتج عن جريان مائع خلال أنبوب يحتوي على حاجز في منتصفه

Abstract

In this work theoretical study is carried out to the effect of heat flux on inducedvibrations from a fluid flow in a simply and flexible supported pipe with arestriction.The water flow in the pipe is assumed to be fully developed region . Thedynamics of a pipe conveying fluid is described by the transfer matrix approach. Itprovides a numerical technique for solving the equations of motion of forced and freevibrations for simply and flexible support .The pipe is divided into (21) nodes and (20)element along its length.Then, from the pipe analysis equation, a fortran Languagecomputer program has been built to embrace the theoretical and analytical work. Andthen to ensure that the program developing is suitable, it has been compared withanother program called (ANSYS Ver.9) which it use FEM.The Obtained results showthat the transfer matrix method is a suitable technique to compute the eigen modes inaddition to the natural frequency of vibration systems.From this research it has beenfound that the heat flux affects the natural frequencies and the amplitude of vibration .So the increasing the thermal force results in the decreasing of the magnitude of thenatural frequencies. The amplitudes of vibration along the pipe increase as the excitationfrequency is so close to the natural frequencies of the system, and this effect ispredominate than the effect of the heat flux .