Imperial College London
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DrSinaStapelfeldt

Faculty of Engineering, Department of Mechanical Engineering

Lecturer
 
 
 
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Contact

 

+44 (0)20 7594 7076s.stapelfeldt

 
 
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Assistant

 

Mr Peter Higgs +44 (0)20 7594 7078

 
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Location

 

556City and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Stapelfeldt:2020:10.1016/j.jsv.2020.115649,
author = {Stapelfeldt, S and Brandstetter, C},
doi = {10.1016/j.jsv.2020.115649},
journal = {Journal of Sound and Vibration},
pages = {1--20},
title = {Non-synchronous vibration in axial compressors: lock-in mechanism and semi-analytical model},
url = {http://dx.doi.org/10.1016/j.jsv.2020.115649},
volume = {488},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Non-Synchronous-Vibration (NSV) in high-speed turbomachinery compressors is an aeroelastic phenomenon which can have devastating consequences, including loss of rotor blades. Despite extensive research over the past two decades its underlying mechanisms are not yet understood. This paper aims to explain the physical mechanisms causing NSV in a modern transonic compressor rotor. Referring to previous experimental results and using validated computational fluid dynamics (CFD), a parametric study is performed in order to characterize the aerodynamic disturbance causing NSV, and to understand the lock-in mechanism between the fluid and the structure seen during NSV. The results show that the process is driven by aerodynamics in the tip region. Under highly throttled conditions, the tip leakage flow blocks the passage and causes the disturbance, which is characterised as a vorticity fluctuation, to propagate circumferentially in the leading edge plane. It is found that the propagation speed of the disturbance is determined by the mean flow conditions and only its phase is periodically modulated through interaction with oscillating blades. This is the mechanism facilitating lock-in. Based on these findings a semi-analytic model is developed and calibrated with the numerical results. The model is capable of simulating the lock-in process and correctly predicts unstable vibration modes. It can therefore be used to identify critical operating conditions and develop mitigation measures early in the design.
AU  - Stapelfeldt,S
AU  - Brandstetter,C
DO  - 10.1016/j.jsv.2020.115649
EP  - 20
PY  - 2020///
SN  - 0022-460X
SP  - 1
TI  - Non-synchronous vibration in axial compressors: lock-in mechanism and semi-analytical model
T2  - Journal of Sound and Vibration
UR  - http://dx.doi.org/10.1016/j.jsv.2020.115649
UR  - https://www.sciencedirect.com/science/article/pii/S0022460X2030479X
UR  - http://hdl.handle.net/10044/1/83964
VL  - 488
ER  -
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