Circular ring
A circular ring is the area between two concentric circles , i.e. H. between two circles with a common center. Its area is
- ,
where is the number of circles and and mean the radii as well as and the diameter of the outer and inner circle.
The area can also be calculated from the inside diameter or outside diameter and ring width :
This information can be found e.g. B. with pipe cross-sections; where is the wall thickness.
Furthermore, the area can be calculated using the annulus width and the mean annulus diameter
- .
The effective hydraulic diameter for a circular ring for hydraulic applications is
- .
Should z. For example, for brake discs , a frictional torque to the axial force and the coefficient of friction by
are determined, the friction-relevant radius calculated or diameter by
- or .
See also
Torus , hollow cylinder , spherical shell
Web links
Individual evidence
- ↑ http://www.schweizer-fn.de/stroemung/druckverbindungen/druckbeispiel.php#hkreisring
- ^ H. Hinzen: machine elements . Volume 2. Oldenbourg Verlag, 2001