Can someone explain how oil whip occurs and its effects on generator-turbine vibration? What are some signs that oil whip is evident?

Oil whip is caused by an unstable oil stimulus in the bearing oil film. It develops as a complex function of journal peripheral speed, oil viscosity, bearing shape, radial bearing load, and journal attitude angle. Misalignment can contribute to the whip condition by changing the bearing loading. Some corrective action for oil whip included the following:
1. additional journal loading by an alignment change
2. reduce oil wedge pressure by additional drainage or leakage area
3. lower oil viscosity
4. use of special bearings to add to unit stability

Oil wip instability develiops when the high pressure wedge creates a lifting force that is greater tan the journal weight causing the journal to momentarily lift for relief. the resonant frequency will often determine whip frequencies. I hope this helps answer your question...
regards,
Tim