关键词: 风扇叶片;扭转特性;弹性变形角;叶尖定时;扭转振动

Abstract: In order to study the torsional characteristics of the fan blade tip， a new dynamic measuring method for blade tip elastic deformation angle of an operating engine based on blade tip timing technology is proposed. The first stage blade tip torsional characteristics of a low bypass ratio two-stage fan were investigated under different operating conditions during rig test of the compressor. The results show that the elastic deformation angle increases with rotational speed and increases while the compressor characteristic curves approaching unstable region. The maximum deformation angle of 1.25° was recorded near the surge point at 100% corrected speed. Variable inlet guide vanes （VIGV） angle has a significant impact on the elastic deformation angle only when operating near the surge line. Elastic deformation angle oscillated sharply at surge point at 90% corrected speed with VIGV angle at -5°. It is estimated that the torsional amplitude of blade1 were 0.18° （before surge）， 1.05° （at surge point） and 0.11° （after surge）. It is possible to measure blade vibration by monitoring elastic deformation angle.

Key words: Fan blade;Torsional characteristics;Elastic deformation angle;Blade tip timing;Torsional vibration