On Jun 3, 1:09 pm, Buy_Sell <werksp...@[EMAIL PROTECTED]
> wrote:
> Hi Brendin, I didn't realize that you lived only a few hours from me.
> I'm just outside of Calgary.
>
> Anyway, I just had a look at your website and saw what you were
> talking about regarding your splitters.
>
> A few months ago, I visited Gordon McAndrew in Vegreville, Alberta and
> saw Gordon's homebuilt hovercraft. Gordon was showing me how his
> splitters were setup and I think that you might want to have a chat
> with him. Gordon's splitters are actually set quite low and fairly
> far away from the lift fan. Apparently, if the splitter is too close
> to the lift fan, once the skirt is filled, the pressure comes back and
> actually tries to stall out the lift fan. Gordon noticed that he had
> better performance with the splitter located what looks to be about 10
> inches below the lift fan. Don't quote me on this but do speak to
> Gordon yourself. If you don't know Gordon, then contact me privately
> and I will give you his address and phone number. - werkspace at
> hotmail dot com.
>
> On May 29, 6:19 pm, "Brendin" <some...@[EMAIL PROTECTED]
> wrote:
>
> > Hi Guys,
>
> > I am just about to paint my hovercraft but remembered my splitters
weren't
> > right. They are about 4" from the duct at the greatest point and
about 10"
> > away from the bottom of the lift fan. Dimensionally they were to plan
(very
> > vague) but I have read that they don't work well in this config. I
know
> > Dave Schneider re-did his splitters in 2004. I am planning on running
my
> > new ones about 1/4" under the lift fan and about 2" out from the duct
wall
> > at the farthest point. Is this correct? My current splitters are
about
> > 17" wide and I'm planning on keeping this width on the new ones.
>
> > So does this sound correct? 17" wide by 2" out from duct wall at
greatest
> > point and about 1/4" or less under the lift fan?
>
> > Thanks very much!
>
> > Brendin
That's not really going to work on a 13p.
First, having the splitters that low will allow water to enter the bag
from the splitter, which makes planing out very difficult.
Second, the large gap makes the bag have the same pressure as the main
plenum, which causes a very soft skirt. UH crafts are designed around
an approximately 1.1:1 pressure ratio between bag and plenum. If your
splitter comes right up to the fan, it allows a higher pressure in the
bag than what the plenum gets, and that's what we want here.
It sounds to me like Gordon has too much space in his splitters. In
that case, the extra pressure could overload the engine as well as
cause extreme drag between the bag and the ground.
The idea is to have the splitters fairly close so that the extra
pressure can be generated, and then adjust the opening size to get the
right pressure ratio.
|
