Critical Speed

In solid mechanics, in the field of rotordynamics, the critical speed is the theoretical angular velocity that excites the natural frequency of a rotating object, such as a shaft, propeller, leadscrew, or gear. As the speed of rotation approaches the object's natural frequency, the object begins to resonate, which dramatically increases system vibration. The resulting resonance occurs regardless of orientation. When the rotational speed is equal to the numerical value of the natural vibration, then that speed is referred to as critical speed.

Read more about Critical Speed:  Critical Speed of Shafts, Critical Speed Equation (Nc)

Famous quotes containing the words critical and/or speed:

    His misfortune was that he loved youth—he was weak to it, it kindled him. If there was one eager eye, one doubting, critical mind, one lively curiosity in a whole lecture-room full of commonplace boys and girls, he was its servant. That ardour could command him. It hadn’t worn out with years, this responsiveness, any more than the magnetic currents wear out; it had nothing to do with Time.
    Willa Cather (1873–1947)

    Wait, Kate! You skate at such a rate
    You leave behind your skating mate.
    Your splendid speed won’t you abate?
    He’s lagging far behind you, Kate.
    David Daiches (b. 1912)