X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from rv-out-0506.google.com ([209.85.198.238] verified) by logan.com (CommuniGate Pro SMTP 5.2.11) with ESMTP id 3411162 for flyrotary@lancaironline.net; Mon, 05 Jan 2009 08:36:06 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.198.238; envelope-from=msteitle@gmail.com Received: by rv-out-0506.google.com with SMTP id f6so9159591rvb.7 for ; Mon, 05 Jan 2009 05:35:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:in-reply-to:mime-version:content-type:references; bh=/AUwGCzknhEssSq9OXSytaSrPLlVGmz8P03JFIeakgA=; b=inHjkImhchnuKtI0SR8+LLjdeZKYbQYBkFmU5FVtU4n0fQqt7g0Vvtr/7qpJDvU0bu Pv+7i7n163VpMpOoAJmLQouM/Ubcp21Zm2EHljc+lTCH+1EOOvDVkvoCVjq6HGxvoAxb 9g/3adtCPps7WkS3VacKGQ9aFrvSu0zcqYdfU= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:in-reply-to:mime-version :content-type:references; b=Dps6ZSFw2LbEKkYVY9xp0s0KIYd1qMehNWqD0ooH0EneiSO2YNtlylS6pgxDZL83Wg ymge8I9OY6jBNIy5xChvQahm29LV9VrJf5T6wQNxPt/PT82VOZ/qaD4jFbzc+59aO8zg 2xvUjPHIRKEq3V0GbmASEStDY9NcjzDHj7JFk= Received: by 10.140.207.2 with SMTP id e2mr10361225rvg.251.1231162529318; Mon, 05 Jan 2009 05:35:29 -0800 (PST) Received: by 10.140.166.4 with HTTP; Mon, 5 Jan 2009 05:35:29 -0800 (PST) Message-ID: <5cf132c0901050535m3c657565x5db0412e8781f695@mail.gmail.com> Date: Mon, 5 Jan 2009 07:35:29 -0600 From: "Mark Steitle" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: 20B install issues overcome In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_105609_26005434.1231162529302" References: ------=_Part_105609_26005434.1231162529302 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Mike, Actually, reducing exhaust noise is one of the beneifts of turbo-charging. Mark S. On Sun, Jan 4, 2009 at 8:35 PM, Mike Wills wrote: > 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 t= hat > works. > > Mike Wills > > ----- Original Message ----- > *From:* Mark Steitle > *To:* Rotary motors in aircraft > *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 signific= ant > reduction. I think I still have the drawings you provided. The nice thi= ng > 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 ro= ot >> of the blades (pusher). It occurs to me that having my exhaust exit thro= ugh >> the prop may help reduce or mask the exhaust noise. On a takeoff roll t= here >> 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, th= ey >> usually tell me that they can hear me before they can see me. ;-( >> >> 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 y= our >> muffler is holding up well? >> >> 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, >> >> That's a great shot. Have you had any "significant issues" with your >> install? If so, how did you overcome them? >> Mark S. >> >> 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 fi= rst >> installed in a composite airplane. I had some kind of electrical noise >> related corruption of settings which persisted through a lot of effort f= or >> over a years time. It has been resolved, and the engine running fine. T= hat >> 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. Th= e >> theory was that the differential pressure below/above the wing would hel= p >> provide the necessary air flow. Not the case here as the location is to= o >> 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 eventu= ally >> install some sort of air flow adjustment, or even consider installing a >> thermostat in the engine. You may recall discussion of these changes he= re >> 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 >> >> >> >> >> >> >> >> >> > > ------=_Part_105609_26005434.1231162529302 Content-Type: text/html; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline
Mike,
 
Actually, reducing exhaust noise is one of the beneifts of turbo-charg= ing.
 
Mark S.

On Sun, Jan 4, 2009 at 8:35 PM, Mike Wills <rv-4mike@cox.net&g= t; wrote:
Well when the E-Racer that was built b= y 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 -----
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, 6= db 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 th= e Hushpower 2 is now.  We'll see.

Mark

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

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

<= span style=3D"FONT-SIZE: 12pt"> 

My exhaust exits about 6-7 inch= es from prop and goes through near the root of the blades (pusher). It occu= rs to me that having my exhaust exit through the prop may help reduce or ma= sk the exhaust noise.  On a takeoff roll there is a prop blade breakin= g 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 ma= ke a difference.

 

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

 

Al G

Agre= e.  Unfortunately, that's not a comment I hear.  On the contr= ary, they usually tell me that they can hear me before they can see me.&nbs= p; ;-( 

Mark S.
ANR headsets mandatory

<= span style=3D"FONT-SIZE: 12pt">On Sun, Jan 4, 2009 at 12:22 A= M, Al Gietzen <A= LVentures@cox.net> 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 you= r muffler is holding up well?        

Mark S.

 

So far it is doing fine.  And th= e 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 rid= e, 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 re= st.  I consider that to be 'expert testimony'J.

Al G

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

Al, =

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

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. &= nbsp;I had some kind of electrical noise related corruption of settings whi= ch persisted through a lot of effort for over a years time. It has been res= olved, and the engine running fine.  That has been discussed here more= than once in the past.

The other was less-than-expected perfor= mance of an oil cooler built into the wing root, without much of a scoop fo= r the inlet below the wing.  The theory was that the differential pres= sure 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 t= he strake (the inboard section on the canard airplane).  The pressure = differential turned out to be only about 1" H20 =96 very little help.&= nbsp; I added a ram scoop, and installed a small oil/water heat exchanger i= n the cowl.  Currently oil temps are fine, and the coolant temp is run= ning 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 t= he engine.  You may recall discussion of these changes here in the pas= t as well.

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

Al G   http://members.cox.net/alg= 3/airplane.htm

 

 

 

<= span style=3D"FONT-SIZE: 12pt"> 



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