Let me clarify a few things about critical speed and "half critical speed" and ask for new response. First, I have seen the effects of running at/near critical speed and have done many tests of overspeed trip systems and will do everything I can to avoid either condition.
More specifics about...
What is the importance of the half critical speed? I have heard that it is an issue in long slender shafts -- l/d 15 to 25 -- but have not personally seen stabilty problems under that condition. I keep hearing people insist on it as a design parameter, but none has given me a reason or...
