From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: Fw: Swirl tank volume?
To: flyrotary
Date: Sun, 15 Sep 2002 21:50:17 -0400
Message-ID: <web-1734111@logan.com>
In-Reply-To: <000501c25d15$e9e6ab20$3a2fd1d8@yvoncournoyer>
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Posted for "GERYVON" <geryvon@sympatico.ca>:
> > Jerry Hey wrote:
> > >
> > > >  > Paul,
> > > >>  Has there been any reference data to calculate the necessary
volume
> of the
> > > >>  swirl tank? How do you decide if you need one? It looks like some
> > > >>have them and
> > > >>  some don't.
> > > >>  Thanks
> > > >>  Dean
> > > >
> > > >Most automotive systems don't use swirl tanks and they work quite
well.
> > > >I am going to try it with out and just copy an automotive system
> exactly.
> > > >After all, billions of dollars have gone into developing automotive
> > > >cooling systems. If it will work for a 6000 pound truck pulling a
> > > >7000 pound load up an 8% grade in So Cal at 65 MPH  on a 100 F
> > > >day it will work for an airplane.
> > > >
> > > >People flying use all sorts of different plumbing systems. I cannot
at
> this
> > > >time identify why some plumbing systems work well and others don't.
> > > >It is buried in too many other factors.
> > > >
> > > >I CAN see why some cooling system don't work for aerodynamic reasons
> > > >and that problem  appears to be at the top of the list. In that
> > > >category having the back side of the rad too close to an object
> > > >seems to be the main reason. Second is not having enough
> > > >air outlet area for the cowl. Third is having a poorly shaped
> > > >inlet duct. Having a radiator that is too small is way down
> > > >the reason list. Most are too large given all the other mistakes.
> > > >The exact plumbing system used is probably at the bottom
> > > >of the reason list.
> > > >
> > > >We still have not got to the point where we are considering cooling
> > > >drag as nobody is yet using cowl flaps to my knowledge.
> > > >
> > > >This is the way I see it now.
> > > >
> > > >Paul Lamar
> > >
> > > I think the difference is that automobiles universally have radiators
> > > with one of the tanks above the engine.  If the rad is below the
> > > engine you will need a swirl pot.    Race cars with low radiators
> > > have swirl pots.  Jerry
>
> I have a large radiator lying flat in the bottom of the aft fuselage, well
> below and far from the engine. I have a simple small overflow tank and no
> swirl pot. The rear housing heater outlet and smaller top outlet are both
> connected back to the coolant pump.
> I flew again yesterday. The weather was cool, (about 15C-60F)  dry and
> windy. Coolant and oil temperatures went to 200-210F on climb out as they
> usually do. Cruising at 3-4000 ft after a few minutes (after some time)
the
> temps stabilized at coolant 160 and oil 180-5.
> My coolant temp sensor is in the rear housing in the standard Mazda
> location. My oil temp sensor is in the oil pan in the standard Mazda
> location.
>
> Paul, I have never seen the coolant at 160 in flight before. After I
> mentionned high temperatures in cabin compounded by hot air trapped in
rear
> fuselage, you suggested hot air exits under the stabilator. I tried that
and
> it appears to be quite efficient, for the engine cooling as well. Thanks
for
> the
> tip.
> Yvon Cournoyer

I addressed this last message to ACRE NL  on Sep 13. It has not appeared on
the ACRE NL yet. I still want Jerry Hey to receive it. So here it is.
Yvon Cournoyer.