Optimal independent modal space control of a fluid-conveying cantilever pipe with flutter instability

• Main Authors: Tung-Wen Liu, 劉童文
• Other Authors: Yih-Hwang Lin
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/37678420974307364203

碩士 === 國立臺灣海洋大學 === 機械與機電工程學系 === 95 === This study deals with the active vibration control of cantilever pipes conveying fluid. The structural instability, such as flutter of a cantilever pipe, will occur due to conveying super-critical flow speed. Both the pipe and the actuator dynamics are considered for establishing the system’s equations of motion for the control formulation. The structural vibration is controlled by using the independent modal space control (IMSC) approach which has the advantages of being able to direct the control on the unstable mode only, reducing the computation significantly, and greatly decreasing the storage requirement. This study deals with a system possessing complex modes, with the unstable mode’s real part being bigger than the imaginary part. This disables the applicability of one important modified IMSC formulation, and the pioneers’ approach, unfavorable in the general cases, must be applied to overcome the difficulties. This study reveals, for the first time, the applicable stability analysis for the development proposed by the IMSC pioneers and turns the table around by changing the originally unfavorable control characteristics to become a favorable one.