Free vibration analysis of fluid conveying tubes

• Main Author: Ganesan Radhakrishnan
• Other Authors: Sellakkutti Rajendran
• Format: Theses and Dissertations
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/54721
• Institution: Nanyang Technological University

Vibration in fluid conveying tubes is studied in this present work. Finite element analysis is carried out to study both axial and transverse free vibrations in tubes which convey fluid at a constant velocity. The partial differential equations governing both axial and transverse vibration in fluid conveying tubes are derived separately. The elemental matrices are derived which are then assembled to obtain the global matrices of the system. The matrix equations are then solved for defined problems in the software MATLAB. The tubes lose their stability when the velocity of the fluid reaches a threshold limit, which is called the critical velocity. Both axial and transverse vibration in fluid conveying tubes is studied with and without damping due to the surrounding medium. The problem is solved for fixed - fixed boundary condition. Nondimensionalisation of the problem is carried out for all the problems and are solved to have a better understanding. Nondimensional parameters are introduced to study the effect of flow velocity on the free vibration of tubes. Partial verification of the problem is also done when the tube vibrates with no fluid inside. The variation of the natural frequency with increasing flow velocity and increasing viscous damping coefficient are tabulated and plotted in graphs. The fundamental mode shapes are also plotted.