Abrasive flow finishing

[Terry Martin]

bmccord at whittman-hart.com wrote:
> 
> Sounds like what you are saying is that the bumps or dimples cause a thin
> layer of turbulance around the ball/object causing it to be "less sticky"
> to the air around it?
> 
> terry_martin at mindlink.bc.ca on 12/17/97 06:26:47 PM 
> Bang on. A perfectly smooth surface will produce a laminar flow, which
> will "pull" away from the surface in small areas, disrupting the laminar
> flow, and causing turbulence. The "bumps" or "dimples" increase the
> surface area over which the airflow occurs, reducing the "pull" on the
> specific point that will break away into the laminar flow.

Some day Microsoft will blow Netscape away by putting direct draw
capabilities into the e-mail window. :-) Then I would just draw a
diagram.

Not less "sticky", which implies adhesion, but a micro laminar flow on
the dimple or bump, which causes less turbulence in the main flow. In
other words the reduction of turbulence by introducing a bump, exceeds
the drag of the bump itself. It also adds "distance" in the length of
the flow at the surface boundary, which causes the air to lose relative
pressure, and heat. The cooler, less energetic air produces less
turbulence from molecular activity, ie as in the ripples you see in the
air over a desert.

Terry

"I accept full accountability for my mistakes, and give full credit to
others for teaching me well in what I get right"