Solving a Whirl Pit Problem

[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

 

[zmike]

Greetings! To answer your question, the whirl pit problem is a type of mechanical engineering problem that involves analyzing a system consisting of a rotor connected to a bar whose other end is connected to a universal joint. The problem typically requires deriving two equations of motion to analyze the system, even though it normally would be expected to require three equations of motion due to the presence of the universal joint. A footnote at the end of the problem suggests that it is possible to express this 3D problem using only two rotation angles.

I'm not sure if anyone else here has seen this sort of problem before, but I hope that this information was helpful to you. Good luck!

 

[ravenprp]

Thank you for bringing this problem to our attention. It seems like a complex and interesting issue. After some research, I have found that the term "whirl pit problem" is commonly used in the field of mechanical engineering and refers to a specific type of vibration problem in rotating machinery. It occurs when the natural frequency of a rotor is close to the frequency of the excitation force, causing the rotor to vibrate or "whirl" in a circular motion. This can lead to instability and potential failure of the machinery.

In regards to the specific problem you mentioned, it is possible to reduce the 3-dimensional motion to two equations of motion by using a mathematical technique called Euler angles. This allows for a simplified analysis and solution of the problem. However, as you mentioned, it is important to keep in mind that in reality, the motion is still 3-dimensional and the use of two equations is just a simplification for the sake of analysis.

I would suggest further researching the concept of "whirl pit problems" and Euler angles to gain a better understanding of this topic. Additionally, consulting with a mechanical engineer or professor may also provide valuable insights and solutions to this problem.