Analysis of Vibration Characteristics of Turbomachine Blade

• Main Authors: Le-Chang Hsiung, 熊樂昌
• Other Authors: Ching-I Chen
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/87674739154579109249

碩士 === 中華大學 === 機械與航太工程研究所 === 88 === The purposes of this thesis are to develop the mathematical modal of turbomachine blade system by using finite difference method, and to study its bending vibration characteristics. There are two main objects in this thesis, single blade system and grouped blade system. The results that from references and finite element software ANSYS will be used to verify the mathematical model in this research. In the single blade system, the mathematical modal was derived from the Euler beam theory and the boundary conditions of Cantilever beam, which can be solved by second-order finite difference method. The influence of taper and pre-twist effects on its bending vibration characteristics will be discussed. A grouped blade system can be considered as a system that a shroud links many single blades, so its dynamic characteristics are more complex then single blade system. Based on the Euler beam theory to find the kinetic energy and strain energy of the grouped blade system, and the governing differential equation and boundary conditions are derived by using Hemilton principal, and find the system reactive numerical solutions with first-order and second-order finite difference methods. Because of the special boundary conditions of grouped blade system, the cantilever modes and fixed-supported modes will be excited. Therefore, the main purpose of this object is to discuss the effects on cantilever modes and fixed-supported modes, which caused by taper, stiffness of root, rotation, radius of disk, stagger angle and number of blades.