Rotating vs. Non-Rotating Cylinder Moving Through Air

[gmbst22]

Hello,

We are working on an application to guard a rotating shaft. The air speed over the shaft is variable from 0-50mph. With the guard in place we can calculate the convection coefficient because it is a cylinder going through air. Is the convection increased in the case of the non-guarded shaft because not only is the cylinder going through air, it is rotating in it as well? Does anyone know of a book that contains a sample of this situation?

Thanks,
Greg

 

[alexit]

In our machine tool applications we theorize that the shaft is an eccentric lobe (maybe with very very small eccentricity) so when operating within the guard this is the same as a single lobe impeller pump. Thus the air both gains rotation vector and is displaced axial according to the fit to the guard and any net angular misalignment between guard and shaft.

When the guard is not present, change the fit to very large and the convective flow will still adjust in proportion to the shaft velocity.

Maybe look to kreila.com