Quote:
Originally Posted by Northy
There is a little more to generating pack, but that means we need to discuss fluid dynamics also 
Anyway, if you have a 3 hole piston setup an 2 hole piston setup with the same static damping then the 3 hole setup will create more pack.
G |
I'd be interested to hear more Northy.....
By static damping, I guess you mean the same viscosity oil (and stiffness of spring)? Also when you talk about 2 and 3 holes I presume they're all the same diamater?
Have to admit I can't stop thinking about this since I read your post
, but my thoughts are:
Increased pack results from increased shear stress, with shear stress proportional to the velocity gradient and viscosity being the constant of proportionality. Each hole in the piston will have a velocity gradient associated with the fluid passing through it, so by adding more holes you increase the total shear stress and therefore the force required to move the piston.
An extra hole does present more area for the fluid to pass through, but I'm assuming in this instance where viscosity is relatively high and the areas (and change in area) are small, viscosity effects, and therefore shear, dominate.
Would you expect the same effect if you only increased the diameter of the existing hole(s)? I'm thinking not, as (for the same velocity) the velocity gradient, and hence shear stress, will be decreased.....
Am I close, or have I just wasted several hours of my life?