13 Apr
2006
13 Apr
'06
12:28 a.m.
* Kerry Mitchell <lkmitch@gmail.com> [Apr 13. 2006 08:10]:
In jet engines, there are series of blades in the fan. Each stage is composed of a rotating blade and a stationary blade. Often the numbers of blades on the rotor and stator are different primes, or at least coprime, in order to reduce resonance from one blade to the next.
Kerry Mitchell --
Transmission with motorcycle: coprime cogwheels. Then with bicycles you have several cogwheels at the rear and want to ensure coprimeness with all possible sets at the rear (ant the front wheel is bigger than all rear wheels). Use a prime number of tooth for the front one.