[NSRCA-discussion] Cooling outrunners

[Dean Pappas]

Hi Jim,
Now that was some neat stuff! Thanks for pointing it out.
Okay, the fancy fairing behind the spinner in the Sea Fury solved the problem of
centrifugal pumping from the back face of the spinner backplate, as well as
guiding the airflow inward. I guess we still need to close up the holes
where the prop blades come out of the spinner. 

 later,

Dean Pappas
Sr. Design Engineer
Kodeos Communications
111 Corporate Blvd.
South Plainfield, N.J. 07080
(908) 222-7817 phone
(908) 222-2392 fax
d.pappas at kodeos.com


-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of J.Oddino
Sent: Wednesday, December 20, 2006 1:18 PM
To: NSRCA Mailing List
Subject: Re: [NSRCA-discussion] Cooling outrunners


I do remember Don's Cutlass.  I thought I'd be the only one old enough.  I
suspect we'll  see a "new" look on the nose of pattern birds that won't be
too different from his design.
I'd like to thank everyone who responded to this topic and I'd like to pass
on a link that Don and Chris Atwood sent.  You need to read it a couple of
times but I concluded the annular opening is probably the most straight
forward approach.  Using the spinner as a centrifugal pump and pumping air
out the front and out the prop cutouts is kind of intriguing though.

http://www.djaerotech.com/dj_askjd/dj_questions/turbo_spinner.html

Jim O


----- Original Message ----- 
From: "Dean Pappas" <d.pappas at kodeos.com>
To: <chad at f3acanada.org>; "NSRCA Mailing List"
<nsrca-discussion at lists.nsrca.org>
Sent: Wednesday, December 20, 2006 7:13 AM
Subject: Re: [NSRCA-discussion] Cooling outrunners


> Hi again,
> The annular cooling entry can be done poorly too!
> Go google the cooling setup on a Hawker Sea Fury. There was a fairing
behind the
> spinner to help the air flow inward toward the crankshaft,
> and the radiators were set far enough aft that there was a decent volume
plenum in front of them.
> The Pletty needs a drive washer extension in order to make the annular
intake work at all,
> the front of the motor hides too closely behind the spinner backplate.
>
> As for the aesthetic issue, who rememebers Doc Coleman's Cutlass Supreme?
>
> later,
>
> Dean Pappas
> Sr. Design Engineer
> Kodeos Communications
> 111 Corporate Blvd.
> South Plainfield, N.J. 07080
> (908) 222-7817 phone
> (908) 222-2392 fax
> d.pappas at kodeos.com
>
>
> -----Original Message-----
> From: nsrca-discussion-bounces at lists.nsrca.org
> [mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Chad
> Northeast
> Sent: Wednesday, December 20, 2006 12:29 AM
> To: NSRCA Mailing List
> Subject: Re: [NSRCA-discussion] Cooling outrunners
>
>
> We actually asked ZN about producing an add-on piece to do just that on
> the Twister while at the Worlds in France.  They were concerned about
> making a composite piece that small strong enough so it never really
> went past discussion.
>
> Dez however, did run a smaller spinner on his motor for a while.  IIRC
> it made a small difference to the temperature but not enough to overcome
> the  decreased aesthetics :)
>
> The motors are around 2.25" OD, spinners up around 3.25"+, so even
> dropping down to a 2.75" spinner still provides a lot of blockage to the
> motor can.
>
> Chad
>
> Rcmaster199 at aol.com wrote:
> > One way this could be done is to allow enough annular room around the
> > spinner, completely bypassing the cheeks and chin. You only need about
> > 1/8" annular opening. Just use a smaller spinner than needed and
> > fashion the model nose to recess the spinner slightly into the annulus.
> >
> > I have done that on Temptress (engine powered) with good results.
> >
> > Use the cheeks and chin to route air to the bats.
> >
> > MattK
> >
> > In a message dated 12/19/2006 9:28:10 AM Eastern Standard Time,
> > bob at toprudder.com writes:
> >
> >     */Chad Northeast <chad at f3acanada.org>/* wrote:
> >
> >         The problem with a lot of composite fuse models (Twister
> >         included) is
> >         that the inlets in the chin and cheeks are often right at the
> >         rear or
> >         even behind an outrunner.....so ducting toward them is very
> >         difficult.
> >         I have to agree that a proper ducting system is crucial for
> >         cooling. I
> >         use a very simple short radius 90 bend in a peice of depron
> >         that pulls
> >         air in from the chin, I see about a 20C rise in temp without
> >         it, other
> >         than that I dont really do anything special. The motor will
> >         operate at
> >         up to 170F without complaining so as long as its 20-30F below
> >         that all
> >         is good :)
> >
> >         Chad
> >
> > ------------------------------------------------------------------------
> >
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