Abrasive flow finishing

[bmccord at whittman-hart.com]

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

Please respond to diy_efi at efi332.eng.ohio-state.edu

To:   diy_efi at efi332.eng.ohio-state.edu
cc:    (bcc: Billy McCord/Whittman-Hart LP)
Subject:  Re: Abrasive flow finishing




Dan wrote:
> The dimples have to be in a random pattern, else you increase
> drag.  The theory is that random dimples (or chevrons) reduce
> bursting near an aerodynamic surface.  Busting is caused by
> low speed air streaks near the wall and is believed to be
> responsible for creating intense turbulence.
>
> Comments?
>
> Dan L
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.