Abstract
It is well known that zero and one nodal diameter (k=0 and k=1) modes of blade system interact with shaft system. We discus experimentally and theoretically the k=1 modes of blade system. If we excited the shaft at the rotational speed of Ω=|ω_b-ω_s|, we examined that the exciting frequency ν=ω_s induced shaft-blade coupled resonance. In addition, we encountered the abnormal vibration below. In the case of the in-plane blade system, blades resonate at Ω=ω_b attributed to deformation caused by gravity. In the case of the out-of-plane blade system, blades are generated at Ω=ω_b/2 due to unbalance of the shaft and asymmetry of the bearing stiffness, and a nonlinear self-exited vibration occurred by galloping due to the cross-section shape of blade tip. Both occurred at the same time and the entrainment phenomena were identified. This paper also includes experimental data of 45deg. blade system.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have