A whirl pit problem

1. Dec 4, 2004

tardon007

Gentlemen,

I have come across this term "whirl pit problem" , a couple of days back and was trying to make out what it was from that point.

it was mentioned in relation to a problem which had a rotor connected to a bar whose other end in connnected to a universal joint which is rotating at a constant angular velocity. the problem intended to derive a two equations of motion. I was surprised because in presence of a universal joint, we would have a 3-d motion and should normally expect 3 equations of motion.

A footnote at the end of the problem indicates that it is possible to express this 3-d problem using two rotation angles only.

I hope that some one amongst you might have seen this sort of problem prior had and if that is so your insight would be appreciated.

regards