Session: 40-09 Fan and Compressor Vibrations

Paper Number: 129094

129094 - Non-Synchronous Vibration and Related Tip Clearance Flow Characteristic in a Low-Speed Axial Fan 

Experiment study related to the flow-induced vibration phenomenon caused by rotating instability flow was conducted on the single-stage axial fan. During the experiment, high-amplitude vibration that can cause high-cycle fatigue of the blades was monitored, and a wire mesh casing treatment was used successfully   suppressed the vibration. The experiment was conducted using two blade materials, metal and nylon, under two different tip clearance conditions. Under the reference blade tip clearance condition, no vibration that could cause blade high-cycle fatigue was found, and there was no rotational instability flow phenomenon. In the case of enlarged tip clearance with nylon blades, as the throttling proceeds, the azimuthal mode decreases. When the frequency in the rotating frame of reference is close to the blade vibration frequency, it will cause the blade to exhibit high-amplitude non-synchronous vibration, accompanied by sudden changes in the azimuthal mode of the unsteady flow. In the same clearance condition with metal blades, the azimuthal mode decreases without sudden change. In response to this phenomenon, this paper conducts some mechanism analysis on the mode and the frequency of the rotational source. Under the same enlarged tip clearance configuration, a wire mesh casing treatment was tested. While expanding the stability margin, it successfully suppressed the high-amplitude vibration phenomenon occurred in the near-stall area.

Presenting Author: He Zhang Research Institute of Aeroengine, Beihang University

Presenting Author Biography: none

Authors:

He Zhang Research Institute of Aeroengine, Beihang University
Ming Zhang School of Energy and Power Engineering, Beihang University
Xu Dong Research Institute of Aeroengine, Beihang University
Dakun Sun School of Energy and Power Engineering, Beihang University
Xiaofeng Sun School of Energy and Power Engineering, Beihang University