X-Virus-Scanned: clean according to Sophos on Logan.com X-PolluStop-Diagnostic: (direct reply)\eX-PolluStop-Score: 0.00\eX-PolluStop: Scanned with Niversoft PolluStop 2.1 RC1, http://www.niversoft.com/pollustop Return-Path: Received: from [24.25.9.100] (HELO ms-smtp-01-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3c4) with ESMTP id 862088 for flyrotary@lancaironline.net; Fri, 08 Apr 2005 15:09:56 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.100; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-185-127.carolina.res.rr.com [24.74.185.127]) by ms-smtp-01-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j38J98Lw000781 for ; Fri, 8 Apr 2005 15:09:09 -0400 (EDT) Message-ID: <001001c53c6e$76566610$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Ed Anderson Cooling System Date: Fri, 8 Apr 2005 15:09:17 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000D_01C53C4C.EF0DFEA0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_000D_01C53C4C.EF0DFEA0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Doug, No doubt when you have different (higher?) standards they can be tougher = to meet {:>). I agree with you assessment about a "reverse venturi" duct. I have a = larger "capture area" before the one duct necks down to 10 sq inches and = the other to 18 sq inches. My theory was that would increase the = velocity (dynamic pressure potential) to help maintain that higher dome = of pressure in front of the core that my radical curved duct walls = infringe on. My inlet is 6" long on one side and 3" long on the other, = so did not have a lot of room to play duct with. I flew a max power/climb take off two days ago with the ground OAT was = 85F, by the time I hit 3000 MSL the oil temp was up to 210F and the = coolant to 220F (my personal maxs for short duration). I then leveled = off and let the cooling system catch up with heat load. So it does = appear that for mid summer operation a bit more inlet area is called = for. I intend to open up the 10sq inch side (which is on my hottest = radiator - first in the series) to 18 sq inches as well. That will = provide a bit more margin on those hottest days. My personal experience = with the 91 turbo block and the Teflon coat silicon coolant "O" rings = that even coolant temps of 240F for short periods do not appear to have = done any harm - as you say, coolant and combustion chamber are still = separate. But, I am please with the experiment in that I believe for my HP engine = (I estimate 175-180HP) I have found a "lower" limit on duct size. = Although perhaps with "exhaust augmentation" it could be made to work = fine in hotter days - much easier just to open one duct up a bit. I total agree, when approaching trees or a ridge line - who cares about = the temps - can always replace the engine (if necessary) provided you = clear the tree line. It always a personal pleasure to exchange ideas, experiences and = theories with people of the calibrate we have on this list. I always = report my happenings - even when they are a bit embarrassing at times. = I seem to have had an unusually assortment of events happen. I was = awarded the Rotary Round Up "Lightening strikes six times (or more) = award which lists a litany of things from oil pump key drop out, front = tire gauges on both sides by the bolts holding on the wheel pant when I = screwed them in a bit too much and then planted the front tire a bit = hard causing it to balloon out and catch the bolts, flop tube drop off = resulting in a 12 miles engine out glide, etc, etc. =20 But one of the main reasons I share - is life is too short to make all = the mistakes yourself, so my objective is IF you are going to make = mistakes - advance the state of the art and make one I haven't - we = already know how those turned out{:>). Thanks for the comments, Doug. We try our best - and what's great is = when you're wrong, folks will bring it to you attention - in a pleasant = manner. Tomorrow I launch (weather permitting) heading down to join Tracy Crook = and on to Lakeland, Fl for Sun & Fun hope to see a bunch of your folks = down there. Best Regards Ed ----- Original Message -----=20 From: Shearbond@aol.com=20 To: Rotary motors in aircraft=20 Sent: Friday, April 08, 2005 11:05 AM Subject: [FlyRotary] Ed Anderson Cooling System In a message dated 4/4/05 6:05:09 PM Mountain Daylight Time, = eanderson@carolina.rr.com writes: There were those who claimed that there was no way that would work. = Well, I reduced my inlet area from 48 sq inch to 28 and it works just = fine thank you. Tracy Crook can vouch that I have flown with the small = openings for well over a year and he has never seen steam or smoke = coming from my engine - yet {:>). Hey Ed...that was probably me! All my analysis uses Military Air = outside conditions (+40 deg F over standard conditions), are climbing at = 100 mph TAS (near max rate of climb) and assumes that you are actually = generating 200 HP. At 2,000 ASL and +40 deg F over standard....I = suspect you are not generating 200HP and if you are indeed capable of = 200 HP probably do not maintain that operating condition sufficiently = long (at 100 mph) to reach steady state conditions which my rules of = thumb consider. =20 Hopefully if you ever are approaching the trees on T/O under the more = severe conditions you can tolerate 245+ deg F engine out coolant = temperature. Been there done that with the Mooney. You know what? The = throttle stayed in WOT and no leaves on the belly! It defined "pucker" = for me. So you'll have to forgive me if I size my inlets just a little = bit larger for our 95 deg summer days. (Military Air at sea level is 99 = deg F)...WOT...generating 200 HP for an extended period!! Do what Tracy = "noodles" and spray water on the heat exchangers!! Of course you have = to carry that two gallons of water around for the inevitable situation = :>). Sort of like a "gear up...not if, but when...if one flys enough. Incidentally we unavoidably reached those 245 deg F engine out = temperatures while developing my friends system without "apparent" ill = effects. He does not have sufficient hours to determine if there were = long term effects, but water and oil are still separate! Being a little = experienced with automotive tests I would estimate that short of rapid = temperature "shock" at those temperatues, no damage was done. Note: = one of the OEM Automotive tests of heads/head gaskets is to dump just = above freezing water into the engine inlet side of the waterpump while = running at full tilt!! That is thermal stress! SWAG (valuable engineering tool), I believe you have what is almost a = reverse venturi duct and your "effective" inlet area is actually larger = than 28 sq. in. which is probably your smallest area in the inlet duct. = I have "noodled" (another valuable engineering tool!) that what you are = doing might very effectively compensate for a very short inlet = duct....but probably is a small detriment to cooling drag. Too small to = matter IMO. Hey, you are a terrific experimenter and an invaluable Hummmmmer flyer = who is willing to share even at the risk of us "still building" asking = questions trying to understand what is happening in the Big RW. It is = terrific you share so we can consider what you have done and if we are = smart....will try to implement same in our own builds. I truly appreciate your combination of theory, practical application = and ability to write!! Thanks! Doug in CO ------=_NextPart_000_000D_01C53C4C.EF0DFEA0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Doug,
 
No doubt when you have different (higher?) standards they can be = tougher to=20 meet {:>).
 
  I agree with you assessment about a "reverse venturi" = duct.  I=20 have a larger "capture area" before the one duct necks down to 10 sq = inches and=20 the other to 18 sq inches.  My theory was that would increase the = velocity=20 (dynamic pressure potential) to help maintain that higher dome of = pressure in=20 front of the core that my radical curved duct walls infringe on.  = My inlet=20 is 6" long on one side and 3" long on the other, so did not have a lot = of room=20 to play duct with.
 
I flew a max power/climb take off two days ago with the ground OAT = was 85F,=20 by the time I hit 3000 MSL the oil temp was up to 210F and the coolant = to 220F=20 (my personal maxs for short duration).  I then leveled off and let = the=20 cooling system catch up with heat load.  So it does appear that for = mid=20 summer operation a bit more inlet area is called for.  I intend to = open up=20 the 10sq inch side (which is on my hottest radiator - first in the = series) to 18=20 sq inches as well.  That will provide a bit more margin on those = hottest=20 days.  My personal experience with the 91 turbo block and the = Teflon coat=20 silicon coolant "O" rings that even coolant temps of 240F for short = periods do=20 not appear to have done any harm - as you say, coolant and combustion = chamber=20 are still separate.
 
But, I am please with the experiment in that I believe for my HP = engine (I=20 estimate 175-180HP) I have found a "lower" limit on duct size.  = Although=20 perhaps with "exhaust augmentation" it could be made to work fine in = hotter days=20 - much easier just to open one duct up a bit.
 
I total agree, when approaching trees or a ridge line - who cares = about the=20 temps - can always replace the engine (if necessary) provided you clear = the tree=20 line.
 
It always a personal pleasure to exchange ideas, experiences and = theories=20 with people of the calibrate we have on this list.  I always report = my=20 happenings - even when they are a bit embarrassing at times.  I = seem to=20 have had an unusually assortment of events happen.  I was awarded = the=20 Rotary Round Up "Lightening strikes six times (or more) award which = lists a=20 litany of things from oil pump key drop out, front tire gauges on both = sides by=20 the bolts holding on the wheel pant when I screwed them in a bit too = much and=20 then planted the front tire a bit hard causing it to balloon out and = catch the=20 bolts, flop tube drop off resulting in a 12 miles engine out glide, etc, = etc. 
 
But one of the main reasons I share -  is life is too short to = make=20 all the mistakes yourself, so my objective is IF you are going to make = mistakes=20 - advance the state of the art and make one I haven't - we already know = how=20 those turned out{:>).
 
Thanks for the comments, Doug.  We try our best - and what's = great is=20 when you're wrong, folks will bring it to you attention - in a pleasant=20 manner.
 
Tomorrow I launch (weather permitting) heading down to join Tracy = Crook and=20 on to Lakeland, Fl for Sun & Fun hope to see a bunch of your folks = down=20 there.
 
Best Regards
 
Ed
 
----- Original Message -----
From:=20 Shearbond@aol.com
Sent: Friday, April 08, 2005 = 11:05=20 AM
Subject: [FlyRotary] Ed = Anderson Cooling=20 System

In a message dated 4/4/05 6:05:09 PM Mountain Daylight Time, eanderson@carolina.rr.com=20 writes:
There were those who claimed that = there was no=20 way that would work.  Well, I reduced my inlet area from 48 sq = inch to=20 28 and it works just fine thank you.  Tracy Crook can vouch = that I have=20 flown with the small openings for well over a year and he has never = seen=20 steam or smoke coming from my engine - yet=20 {:>).
Hey Ed...that was probably me!  All my analysis uses = Military Air=20 outside conditions (+40 deg F over standard conditions), are = climbing at=20 100 mph TAS (near max rate of climb) and assumes that you are = actually=20 generating 200 HP.  At 2,000 ASL and +40 deg F over=20 standard....I suspect you are not generating 200HP and if you are = indeed=20 capable of 200 HP probably do not maintain that operating condition=20 sufficiently long (at 100 mph) to reach steady state conditions = which my=20 rules of thumb consider. 
 
Hopefully if you ever are approaching the trees on T/O under = the=20 more severe conditions you can tolerate 245+ deg F engine out coolant=20 temperature.  Been there done that with the Mooney.  You = know=20 what?  The throttle stayed in WOT and no leaves on the = belly!  It=20 defined "pucker" for me.  So you'll have to forgive me if I size = my=20 inlets just a little bit larger for our 95 deg summer days.  = (Military=20 Air at sea level is 99 deg F)...WOT...generating 200 HP for an = extended=20 period!!  Do what Tracy "noodles" and spray water on the heat=20 exchangers!!  Of course you have to carry that two gallons of = water=20 around for the inevitable situation :>).  Sort of like a "gear = up...not if, but when...if one flys enough.
 
Incidentally we unavoidably reached those 245 deg F engine out=20 temperatures while developing my friends system without "apparent" ill = effects.  He does not have sufficient hours to determine if there = were=20 long term effects, but water and oil are still = separate!  Being a=20 little experienced with automotive tests I would estimate that short = of rapid=20 temperature "shock" at those temperatues, no damage was done. =20 Note:  one of the OEM Automotive tests of heads/head gaskets is = to dump=20 just above freezing water into the engine inlet side of the waterpump = while=20 running at full tilt!!  That is thermal stress!
 
SWAG (valuable engineering tool), I believe you have what is = almost a=20 reverse venturi duct and your "effective" inlet area is actually = larger than=20 28 sq. in. which is probably your smallest area in the inlet = duct.  I=20 have "noodled" (another valuable engineering tool!) that what you are = doing=20 might very effectively compensate for a very short inlet = duct....but=20 probably is a small detriment to cooling drag.  Too small to = matter=20 IMO.
 
Hey, you are a terrific experimenter and an invaluable Hummmmmer = flyer=20 who is willing to share even at the risk of us "still building" asking = questions trying to understand what is happening in the Big = RW.  It=20 is terrific you share so we can consider what you have done and = if we are=20 smart....will try to implement same in our own builds.
 
I truly appreciate your combination of theory, practical = application and=20 ability to write!!  Thanks!
 
Doug in CO
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