fan blade resonances
TRANSCRIPT
Fan Blade resonances
10/21/17 rev A
Don Blanchet
3B Associates
Prepared for:JK Locowitz Aero Ltd.
Solidworks model 10 Blades4.5 inch diaPVC plastic
FEA mesh
10 node tetras210,000Degrees of freedom
Resonance results , hz
Blade fluttering
Mode shape #1
Mode shape #2
Mode shape #3
Mode shape #4
Mode shape #5
Fan speed summary
Vibrationmode
Frequencyhz
FanSpeedRPM
1 672.99 ~ 42,000
2 700.99
3 701.15
4 701.43
5 701.58
Target designSpeed 7,000 RPM
Conclusions
There is a very low risk of fan bladeflutter and resonance producedstresses in this design at 7,000 RPM.
The first prototypes should be testedto 10,000 RPM to establish margin.