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There are many kinds of assembly structures in heavy-duty gas turbine compressor stator blades which have significant influence on the complex damping vibration characteristics. At present, compressor design is becoming more and more compact, so it is very meaningful to accurately obtain stator blade vibration characteristics of structures with contact damping. Firstly, a fretting slip friction dynamic model was introduced, and then a vibration analysis model of the compressor stator blade with outer ring structure was established based on the slip friction theory. Then, the vibration response of the compressor stator blade was obtained according to various working conditions, and the main factors affecting the vibration characteristics of the stator blade were revealed. Finally, the vibration response of the blade under a particular exciting force condition was simulated. The results show that the damping vibration characteristics of the compressor stator blades were affected by the excitation force and the normal load of the contact surface. The vibration response curve of the stator blade and the equivalent stiffness coefficient of the contact surface were analyzed, and the friction motion of the contact surface changed with the change of the working condition. The model can simulate the nonlinear vibration characteristics of stator blades. This method provides a reference for the vibration safety analysis of compressor stator blades.

Within the framework of linear water wave theory, the diffraction of water waves by a hollow circular cylinder in an infinite ocean depth is considered. The whole fluid domain is divided into two regions: interior and exterior regions. Using separation of variables technique, Fourier sine transform and Havelock's expansion theorem, the diffracted potentials in each region are obtained, and consequently the exciting forces and their phase angles are evaluated for different draft and different radius of the cylinder. It is observed that the forces attain higher values in the lower frequency range for higher draft and also for higher radius values. The free surface elevation for both exterior and interior regions is also discussed. As the distance from the cylinder surface increases, the elevation of waves reduces. All the observations are validated through suitable graphs. [ABSTRACT FROM AUTHOR]