Vibration control of loosely supported cross-flow heat exchanger tube undergoing fluid elastic instability

Abstract

Abstract In this theoretical work, the effect of support stiffness in controlling the nonlinear vibration of loosely supported cross-flow heat exchanger tube and support-impact forces is studied. The bending of slender heat exchanger tube is modelled using Euler-Bernoulli beam theory. The cross-flow induced forces on tube are modelled using quasi-steady flow model whereas the loose support is modelled with trilinear spring model. The Galerkin discretisation and time integration are used to solve the nonlinear governing differential equation of motion. From the results, it is observed that with the reduction of support stiffness, the chaotic motion of the tube gradually changes to periodic motion, the drastic changes in the acceleration of the tube during its motion reduces, and also the magnitude of the contact forces greatly reduces. Thus, if the support is made of low stiffness material or placing a low stiffer buffer layer over stiff support, the vibration and impact forces can be significantly reduced..