Restraining springs, opposing the yaw motion of the wheelset, and similar restraints on bogies, may be used to raise the critical speed further.
22.
That meant that for travel above some critical speed, a hovercraft could be more efficient than a wheeled vehicle of the same weight.
23.
But the critical speed thing should be no surprise because drag is a proportional-to-the-cube-of-the-velocity effect-where as A / C cost is irrespective of velocity.
24.
It uses an axial two-staged low pressure ratio subsonic turbine that operates at 65, 000rpm, which is between the second and third critical speed.
25.
That implied that for travel above some critical speed, a hovercraft could be more efficient than a wheeled vehicle running on the same route.
26.
Both calculate an approximation of the first natural frequency of vibration, which is assumed to be nearly equal to the critical speed of rotation.
27.
Critical speed depends upon the magnitude and location of the shaft unbalance, the length of the shaft, its diameter, and the kind of bearing support.
28.
In practice, the swaying is damped out below a critical speed, but is amplified by the forward motion of the train above the critical speed.
29.
In practice, the swaying is damped out below a critical speed, but is amplified by the forward motion of the train above the critical speed.
30.
The kinematic description of the motion of tapered treads on the two rails is insufficient to describe hunting well enough to predict the critical speed.
