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Ok, Bill
Understand your point. I don't like to tear up stuff I've done in any
case {:>). I am really quite pleased with the results so far, even though
Mr. Lamar tends to poop-poop anything I suggest or come up with. I don't
think he's ever quite forgiven me for not falling out of the air with my
"Plugs Up" installation {:>). Just kidding, Paul I and get along fine, we
just disagree on some points {:>)
Ed
----- Original Message -----
From: "William" <wschertz@ispwest.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Thursday, September 04, 2003 9:32 PM
Subject: [FlyRotary] Re: Downsize inlet duct First Flight
> let me clarify: if you use the K&M smoothing technique, but are only able
to
> reduce the opening a "little" bit, instead of down to 9 in^2, you may get
> the same or improved cooling with lower drag. Just don't throw out the
idea
> if 9 in^2 isn't the final answer.
> Bill
> ----- Original Message -----
> From: "Ed Anderson" <eanderson@carolina.rr.com>
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Sent: Thursday, September 04, 2003 8:09 AM
> Subject: [FlyRotary] Re: Downsize inlet duct First Flight
>
>
> > Point well taken, Bill. However, my cooling was more than adequate with
> the
> > old larger ducts, so unless I can get some benefit (like lower drag), I
> > don't see much point. On the other hand, if I added a turbo producing
> more
> > waste heat then that would help there with the same size ducts. I'll
> > continue to see what I can do with it.
> >
> > Ed
> >
> >
> > Subject: [FlyRotary] Re: Downsize inlet duct First Flight
> >
> >
> > > Ed, you might get even better cooling, although no change in drag, by
> > > keeping the opening large, but using the smoothing technique that you
> > tried
> > > on the smaller opening.
> > > Bill Schertz
> > > ----- Original Message -----
> > > From: "Ed Anderson" <eanderson@carolina.rr.com>
> > > To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> > > Sent: Wednesday, September 03, 2003 7:18 PM
> > > Subject: [FlyRotary] Downsize inlet duct First Flight
> > >
> > >
> > > > The modification (reduction) of my radiator inlet duct area from a
> total
> > > of
> > > > 48 square inches to 33 square inches is dedicated to Rusty (for
> obivious
> > > > reasons {:>)) Sorry, just couldn't help myself, Rusty, - the devil
> > made
> > > me
> > > > do it.
> > > >
> > > > Ok folks, made the first flight today with my reduced/reshaped
> radiator
> > > > > inlet for the left evaporator core. The right evaporator core was
> > left
> > > > > unmodified to provide a safety net sufficient to do the pattern
and
> > > land
> > > > if
> > > > > take off temps exceeded expectations. Fortunately, that was not
> > > > necessary.
> > > > > OAT on first take off was a humid 85 degrees. No temperature
> > increased
> > > > > noted during ground run up, so launched and made max rate of
climb,
> > not
> > > > > seeing any abnormal temp increase I left the pattern and continue
> Max
> > > rate
> > > > > climb to 4500 MSL. Max temp of coolant during climb was 210F
> (normal
> > > for
> > > > > max rate climb at these OAT temps is 205F), Max oil temp was 200F
> > > nominal
> > > > > for max power climb. Max temps were reached about 2/3 of the way
> > through
> > > > the
> > > > > climb.
> > > > >
> > > > > In level flight, my coolant temperatures normally run 5 degrees
> colder
> > > > than
> > > > > my oil temp. Today my coolant and oil temps were the same. So
> > average
> > > > > coolant temp was increased by 5 Degrees F. Total radiator inlet
> duct
> > > area
> > > > > was decreased from 48 square inches to 33 square inches. 24
Square
> > > inches
> > > > > for the right inlet duct and 9 square inch inlet for the modified
> > right
> > > > > duct (See attached photo for comparision). Probably some drag
> benefit,
> > > but
> > > > did not try to investigate that
> > > > > aspect.
> > > > >
> > > > > I flew to an airfield 50 miles away to have my transponder
> recertified
> > > and
> > > > > when I launched out of it, the OAT (ground level) was 92F
> > > > >
> > > > > After level off I ran at different power settings to see the
effect.
> > > > >
> > > > > 5800 rpm burning 11.9 GPH at 4500 MSL with OAT at 78F My oil
and
> > > > coolant
> > > > > were both 190F.
> > > > >
> > > > > 5400 rpm burning 9.6 GPH at 4500 MSL with OAT 80F My Oil and
coolant
> > > were
> > > > > both 185F
> > > > >
> > > > > 5200 (Around my normal cruise rpm) burning 7.25 GPH at 4500 MSL
> with
> > > OAT
> > > > 80F My
> > > > > oil and coolant were both 180F
> > > > >
> > > > > In summary, the 33 % reduction in total radiator inlet area
> appeared
> > to
> > > > > have increased coolant temps by an average of 5 Deg above the
normal
> > > (the
> > > > > old duct). It could be that both the remaining radiator and
perhaps
> > the
> > > > oil
> > > > > cooler are rejecting any additonal load with no problem.
> > > > >
> > > > > It appears that smoothing out the path for the air from inlet to
> > > radiator
> > > > > surface has benefited the cooling situation. It could be that
> > > additional
> > > > > heat may be rejected by the right (second in series) radiator as
the
> > > > coolant
> > > > > it received from the left radiator was probably now a bit hotter.
I
> > also
> > > > > observed that the plate of the PSRU covers an area 3 " in from top
> to
> > > > bottom
> > > > > of the rear of each radiator and the plate is only 2" from the
rear
> of
> > > the
> > > > > fins at its closest, so that is obviously not helping flow, the
Ross
> > > Bell
> > > > > housing did not, so a bell housing might improve flow conditions .
> > > > >
> > > > > I strongly suspect I would probably find that a similar
reduction
> > of
> > > > the
> > > > > right radiator inlet duct to 9 square inches would see my coolant
> > (and
> > > > > probably oil) temps increase considerable more than another 5 F.
> > > >
> > > > OAT at ground level was 94F when I landed, so not the hottest of
> days,
> > > but
> > > > not the
> > > > > type I normally prefer to fly in.
> > > > >
> > > > > >From what I have seen so far, I think it worth pursuing a
reduction
> > > with
> > > > the
> > > > > right radiator duct. I will probably not reduce it as much for
the
> > > reason
> > > > > mentioned above. With some other things to take care of, probably
> > won't
> > > > get
> > > > > to it until later part of Sept at the earliest. But, I have no
> > problem
> > > > > flying with current asymmetrical ducts, so will leave it as is for
> the
> > > > time
> > > > > being and collect some more data.
> > > > >
> > > > > It it appears that some cooling benefit is derived from providing
a
> > > > smoother
> > > > > transition from duct to radiator (even if far from a perfect
> > > > implementation
> > > > > of the K&M approach) than my old duct provided. The volume of the
> > duct
> > > > was reduced by at least 60%, so while hard to tell from photos the
> white
> > > > "filler" material actually fills most of the duct.
> > > > >
> > > > > Oh, yes, as an aside, its been 25 hours since I replaced the spark
> > plugs
> > > > and
> > > > > right on schedule - on the way back, I got the first SAG
(Sparkplug
> > > > > Attention Getter) indication. So it appears 25 hours on 100LL
> about
> > > the
> > > > > average time for replacing plugs in my case. I finally got a
spark
> > plug
> > > > > cleaner, so need to clean a set (as the electrods do not appear
> worn)
> > > and
> > > > > see if getting the lead off the ceramic cone helps any.
> > > > >
> > > > > Best Regards
> > > > >
> > > > > Ed Anderson
> > > >
> > > > Ed Anderson
> > > > RV-6A N494BW Rotary Powered
> > > > Matthews, NC
> > > > eanderson@carolina.rr.com
> > > >
> > >
> > >
> >
>
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> > >
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> >
> >
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>
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