- #1
tricha122
- 20
- 1
hi,
I’m trying to understand why in a rotor bearing system that the critical speeds of the rotor are higher for forward whirl, and lower for backward whirl.
My general understanding is that forward and backward whirl frequencies diverge due to gyroscopic effects, and for forward whirl the gyroscopic effect is “stiffening” - and so the critical speeds are higher, and the opposite is true for backward whirl.
I’ve never been able to rationalize this with a FBD or by looking at the equations of motion. Does anyone have a good way to visualize / explain this phenomenon?
Any help would be greatly appreciated, thanks!
I’m trying to understand why in a rotor bearing system that the critical speeds of the rotor are higher for forward whirl, and lower for backward whirl.
My general understanding is that forward and backward whirl frequencies diverge due to gyroscopic effects, and for forward whirl the gyroscopic effect is “stiffening” - and so the critical speeds are higher, and the opposite is true for backward whirl.
I’ve never been able to rationalize this with a FBD or by looking at the equations of motion. Does anyone have a good way to visualize / explain this phenomenon?
Any help would be greatly appreciated, thanks!