Flow Between Parallel Disks 1

[enirwin]

Does anyone know the equation for pressure gradient as a function of radius for viscous flow between two disks? Pressure is applied at the ID and flow is outward. I'm trying to size a thrust washer to react a thrust load in a pump and I need to approximate the thrust capacity of the washer. Thanks.

 

[prex]

If I understand you correctly, you have two facing hollow disks and the direction of flow is radial from ID to OD.
This is the typical setup for flat bearings and you can find their treatment in a book on the lubrication theory.
The resulting formula for pressure as a function of radius is:

6&[ignore]nu[/ignore];W
p= ---- log(r_e/r)
&[ignore]pi[/ignore];h³

&[ignore]nu[/ignore];=viscosity
W=volumetric flow rate
h=(constant) gap between disks
r_e=outer radius
r=current radius

prex

http://www.xcalcs.com

Online tools for structural design

 

[enirwin]

prex,

Thanks. That's exactly what I was looking for. Can you recommend a good text on lubrication theory?

Thanks,

enirwin