블레이드 밀도와 관성 모멘트에 의한 회전하는 패킷 블레이드 시스템의 진동 국부화

초록

Multi-packet blade systems consist of several blades. These blades are connected to a hub and shrouds. The blades of a system are mostly assumed to be perfectly tuned. However, there often exists small, random mistuning in the multi-packet blade system due to manufacturing tolerance, in-operation wear. It may lead to significant increase in the forced vibration responses of some blades in the multi-packet blade system. Critical fatigue troubles often occur in mistuned system is often strikingly larger than that of a perfectly tuned system.Therefore, it is very critical to forecast the maximum blade response. In this paper, blades are assumed as cantilever beams and the flexibilities of the hub and the shrouds are assumed as discrete springs. Equations of motion of the multi-packet blade system are derived by using the hybrid deformation variable method. To investigate the vibration localization phenomena with random mistuning, transient analysis are carried out for the multi-packet blade system excited by multiple nozzle jet forces.

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