Return-Path: Received: from ms-smtp-01.southeast.rr.com ([24.93.67.82] verified) by logan.com (CommuniGate Pro SMTP 4.1.3) with ESMTP id 2568192 for flyrotary@lancaironline.net; Thu, 04 Sep 2003 22:19:52 -0400 Received: from o7y6b5 (clt78-020.carolina.rr.com [24.93.78.20]) by ms-smtp-01.southeast.rr.com (8.12.5/8.12.2) with SMTP id h852Ch0R020645 for ; Thu, 4 Sep 2003 22:12:45 -0400 (EDT) Message-ID: <000801c37353$e3c31a80$1702a8c0@WorkGroup> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Downsize inlet duct First Flight Date: Thu, 4 Sep 2003 22:17:42 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit 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 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" To: "Rotary motors in aircraft" 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" > To: "Rotary motors in aircraft" > 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" > > > To: "Rotary motors in aircraft" > > > 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 > > > > > > > > > > > > > > -------------------------------------------------------------------------- > > -- > > > ---- > > > > > > > > > > >> Homepage: http://www.flyrotary.com/ > > > > >> Archive: http://lancaironline.net/lists/flyrotary/List.html > > > > > > > > > > > > > >> Homepage: http://www.flyrotary.com/ > > > >> Archive: http://lancaironline.net/lists/flyrotary/List.html > > > > > > > > > > > >> Homepage: http://www.flyrotary.com/ > > >> Archive: http://lancaironline.net/lists/flyrotary/List.html > > > >> Homepage: http://www.flyrotary.com/ > >> Archive: http://lancaironline.net/lists/flyrotary/List.html