X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao106.cox.net ([68.230.241.40] verified) by logan.com (CommuniGate Pro SMTP 5.2.11) with ESMTP id 3410786 for flyrotary@lancaironline.net; Sun, 04 Jan 2009 21:35:53 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.40; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao106.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20090105023512.HGNV12540.fed1rmmtao106.cox.net@fed1rmimpo02.cox.net> for ; Sun, 4 Jan 2009 21:35:12 -0500 Received: from wills ([68.105.85.56]) by fed1rmimpo02.cox.net with bizsmtp id zeb81a0071CvZmk04ebAen; Sun, 04 Jan 2009 21:35:11 -0500 X-Authority-Analysis: v=1.0 c=1 a=NSHW2kUv_6QA:10 a=Zgn9d7bnwx8A:10 a=kviXuzpPAAAA:8 a=w1Ede-f2SaDVh_zjBEgA:9 a=QAaXT7PzJz0YmXLP3JoA:7 a=u_kJ1_-yEt3chxlGlfKA0aCVXckA:4 a=4vB-4DCPJfMA:10 a=5FtdkfQUxfIA:10 a=HTPOLumANohLTrXNZHgA:9 a=Tj9hEHmJA18DQf1R7WAA:7 a=texeZpFhDhR9ou4Y17lfmzjfoiAA:4 a=MSl-tDqOz04A:10 a=EzXvWhQp4_cA:10 a=AfD3MYMu9mQA:10 X-CM-Score: 0.00 Message-ID: <002d01c96ede$3b0a0fc0$38556944@wills> From: "Mike Wills" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: 20B install issues overcome Date: Sun, 4 Jan 2009 18:35:10 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002A_01C96E9B.2C9CCE70" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3350 This is a multi-part message in MIME format. ------=_NextPart_000_002A_01C96E9B.2C9CCE70 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Well when the E-Racer that was built by George Graham was on the airport = it was about the only prop plane louder than mine. That airplane was ear = splitting loud. So I'm not sold on the prop as a noise reducer. Give = yourself more credit Al, you've actually engineered and built a muffler = that works. Mike Wills ----- Original Message -----=20 From: Mark Steitle=20 To: Rotary motors in aircraft=20 Sent: Sunday, January 04, 2009 8:45 AM Subject: [FlyRotary] Re: 20B install issues overcome I guess the prop chopping the noise stream could account for some of = the perception of quietness. As for the muffler/resonator, 6db is a = significant reduction. I think I still have the drawings you provided. = The nice thing about the tangential muffler design is that it will fit = inside my cowl. The muffler/resonator should fit where the Hushpower 2 = is now. We'll see. Mark On Sun, Jan 4, 2009 at 10:17 AM, Al Gietzen = wrote: Subject: [FlyRotary] Re: 20B install issues overcome My exhaust exits about 6-7 inches from prop and goes through near = the root of the blades (pusher). It occurs to me that having my exhaust = exit through the prop may help reduce or mask the exhaust noise. On a = takeoff roll there is a prop blade breaking that exhaust stream about = 130 times per second. Let's see, that's about 1 blade passing for every = two exhaust pulses on the 20B =96 could make a difference. The secondary muffler/resonator I have also helps. On the dyno we = measured that resulted in about 6 db reduction. Al G Agree. Unfortunately, that's not a comment I hear. On the = contrary, they usually tell me that they can hear me before they can see = me. ;-( =20 Mark S. ANR headsets mandatory On Sun, Jan 4, 2009 at 12:22 AM, Al Gietzen = wrote: I'm presently gathering materials to fabricate a tangential muffler = made from inconel, similar to your design. I take it from your report = that your muffler is holding up well? =20 Mark S. So far it is doing fine. And the inconel tangential and the 321SS = secondary muffler (my own design) quiet it down nicely. A few days ago = I picked up my brother to go for a ride, while my sister-in-law waited = and watched other planes come and go. When we got back her remark was = that my plane was quieter than all the rest. I consider that to be = 'expert testimony'J. Al G On Sat, Jan 3, 2009 at 5:47 PM, Al Gietzen = wrote: Al,=20 That's a great shot. Have you had any "significant issues" with = your install? If so, how did you overcome them? Mark S. =20 I had 2 issues that required some time and determination. The first = was the RWS EC2. I had an early version for the 3-rotor, and perhaps = the first installed in a composite airplane. I had some kind of = electrical noise related corruption of settings which persisted through = a lot of effort for over a years time. It has been resolved, and the = engine running fine. That has been discussed here more than once in the = past. The other was less-than-expected performance of an oil cooler built = into the wing root, without much of a scoop for the inlet below the = wing. The theory was that the differential pressure below/above the = wing would help provide the necessary air flow. Not the case here as = the location is too far back on the wing; and behind the strake (the = inboard section on the canard airplane). The pressure differential = turned out to be only about 1" H20 =96 very little help. I added a ram = scoop, and installed a small oil/water heat exchanger in the cowl. = Currently oil temps are fine, and the coolant temp is running a bit = lower than I like at cruise. I may eventually install some sort of air = flow adjustment, or even consider installing a thermostat in the engine. = You may recall discussion of these changes here in the past as well. I'm just past 140 hours flying time, and feel quite fortunate with = how well things have worked out. Performance and economy are great. Al G http://members.cox.net/alg3/airplane.htm ------=_NextPart_000_002A_01C96E9B.2C9CCE70 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
Well when the E-Racer that was built by = George=20 Graham was on the airport it was about the only prop plane louder than = mine.=20 That airplane was ear splitting loud. So I'm not sold on the prop as a = noise=20 reducer. Give yourself more credit Al, you've actually engineered and = built a=20 muffler that works.
 
Mike Wills
----- Original Message -----
From:=20 Mark = Steitle=20
Sent: Sunday, January 04, 2009 = 8:45=20 AM
Subject: [FlyRotary] Re: 20B = install=20 issues overcome

I guess the prop chopping the noise stream could = account for=20 some of the perception of quietness.  As for the = muffler/resonator, 6db=20 is a significant reduction.  I think I still have the drawings = you=20 provided.  The nice thing about the tangential muffler design is = that it=20 will fit inside my cowl.  The muffler/resonator should fit where = the=20 Hushpower 2 is now.  We'll see.

Mark

On Sun, Jan 4, 2009 at 10:17 AM, Al Gietzen = <ALVentures@cox.net> = wrote:

Subject:=20 [FlyRotary] Re: 20B install issues overcome

 

My = exhaust exits=20 about 6-7 inches from prop and goes through near the root of the = blades=20 (pusher). It occurs to me that having my exhaust exit through the = prop may=20 help reduce or mask the exhaust noise.  On a takeoff roll there = is a=20 prop blade breaking that exhaust stream about 130 times per second. = Let's=20 see, that's about 1 blade passing for every two exhaust pulses on = the 20B =96=20 could make a difference.

 

The = secondary=20 muffler/resonator I have also helps.  On the dyno we measured = that=20 resulted in about 6 db reduction.

 

Al=20 G

Agree. =20 Unfortunately, that's not a comment I hear.  On the contrary, = they=20 usually tell me that they can hear me before they can see me. =20 ;-( 

Mark S.
ANR headsets = mandatory

On Sun, Jan 4, 2009 at 12:22 = AM, Al=20 Gietzen <ALVentures@cox.net> wrote:

I'm presently=20 gathering materials to fabricate a tangential muffler made from = inconel,=20 similar to your design.  I take it from your report that your = muffler=20 is holding up well?        

Mark=20 S.

 

So far = it is=20 doing fine.  And the inconel tangential and the 321SS secondary = muffler=20 (my own design) quiet it down nicely.  A few days ago I picked = up my=20 brother to go for a ride, while my sister-in-law waited and watched = other=20 planes come and go.  When we got back her remark was that my = plane was=20 quieter than all the rest.  I consider that to be 'expert=20 testimony'J.

Al=20 G

On Sat, Jan 3, 2009 at 5:47 = PM, Al=20 Gietzen <ALVentures@cox.net> wrote:

Al,=20

That's a great shot.  Have you had any "significant = issues"=20 with your install?  If so, how did you overcome them?
Mark = S. =20

I had 2 = issues=20 that required some time and determination. The first was the RWS = EC2. =20 I had an early version for the 3-rotor, and perhaps the first = installed in a=20 composite airplane.  I had some kind of electrical noise = related=20 corruption of settings which persisted through a lot of effort for = over a=20 years time. It has been resolved, and the engine running fine.  = That=20 has been discussed here more than once in the = past.

The = other was=20 less-than-expected performance of an oil cooler built into the wing = root,=20 without much of a scoop for the inlet below the wing.  The = theory was=20 that the differential pressure below/above the wing would help = provide the=20 necessary air flow.  Not the case here as the location is too = far back=20 on the wing; and behind the strake (the inboard section on the = canard=20 airplane).  The pressure differential turned out to be only = about 1"=20 H20 =96 very little help.  I added a ram scoop, and installed a = small=20 oil/water heat exchanger in the cowl.  Currently oil temps are = fine,=20 and the coolant temp is running a bit lower than I like at = cruise.  I=20 may eventually install some sort of air flow adjustment, or even = consider=20 installing a thermostat in the engine.  You may recall = discussion of=20 these changes here in the past as well.

I'm = just past 140=20 hours flying time, and feel quite fortunate with how well things = have worked=20 out.  Performance and economy are great.

Al = G  =20 http://members.cox.net/alg3/airplane.htm

 

 

 

 


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