Re: [PSUBS-MAILIST] Minn Kota - Thrust

[Jon Hylands <hylands@ibm.net>]

On Sat, 11 Mar 2000 22:51:38 -0800, "Wade Carson"
<wacarson@interchange.ubc.ca> wrote:

> The idea of the hull is to move the transition from laminar to turbulent
> flow further back on the hull because laminar flow creates less resistance
> due to skin friction than turbulent flow would.  For an AUV that would be
> fine provided you could get the hull smooth enough but a manned sub must
> have a hatch and a hatch will create a discontinuity in the hull.  Even the
> smallest discontinuity can trip a laminar turbulent transition and ruin the
> benefits that the hull form provides.  In addition, without careful
> analysis, you might discover that a laminar boundary layer will separate
> after the apex and then you're really hooped.

Yeah, the hull-smoothness thing is something they mentioned in the paper. I
have no idea how smooth is smooth enough, but since this particular AUV I
am building is a test platform, it doesn't matter very much.

Later,
Jon


--------------------------------------------------------------
   Jon Hylands      Jon@huv.com      http://www.huv.com/jon

  Project: Micro Seeker (Micro Autonomous Underwater Vehicle)
           http://www.huv.com