X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with ESMTP id 4499081 for flyrotary@lancaironline.net; Fri, 08 Oct 2010 22:33:31 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.1 cv=tl/FS04gSkLncqxOIKBEYmN/gODDJX05BQMXZ5l6AuI= c=1 sm=0 a=DKypqVl7SEcA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:17 a=ayC55rCoAAAA:8 a=Ia-xEzejAAAA:8 a=hZWWvw5yAAAA:8 a=arxwEM4EAAAA:8 a=r1ClD_H3AAAA:8 a=BGnaVvR7lWiO2CmCB4AA:9 a=JxP540SVx0WmswfZPB4A:7 a=4av_i3Y9O9rEyxa7WOLpVUtSKTQA:4 a=wPNLvfGTeEIA:10 a=EzXvWhQp4_cA:10 a=on22okXAAAAA:8 a=E93lBu2AAAAA:8 a=4P2FFwLKqxn4NH7YII8A:9 a=3cy_EJSoWmISM5writcA:7 a=Jmhq8gLxmAi2syI45_zKa4I4e7UA:4 a=at0Q5_2dr5wA:10 a=hO30gm18fF0A:10 a=MpuOTR30KwMA:10 a=FOUTPhXFUAcA:10 a=zgjei8Deq7QA:10 a=NWVoK91CQyQA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.167.5 Received: from [174.110.167.5] ([174.110.167.5:58688] helo=EdPC) by cdptpa-oedge03.mail.rr.com (envelope-from ) (ecelerity 2.2.2.39 r()) with ESMTP id B2/72-19342-754DFAC4; Sat, 09 Oct 2010 02:32:56 +0000 Message-ID: From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Another prop performance calculator Date: Fri, 8 Oct 2010 22:32:48 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000D_01CB6738.BC36D250" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 This is a multi-part message in MIME format. ------=_NextPart_000_000D_01CB6738.BC36D250 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Jeff, Wish I knew something about props, but it seems more black art = than cooling ducts {:>). Having 4 blades with a 74" dia and spinning = 6100 rpm even with 58" pitch would appear to me to indicate a strong = engine. But, you are right, its really hard to compare apples and = oranges. We clearly saw a significant difference in performance between Sam's = prop and mine - on his engine. Sam was clearly delighted to be = producing over 6000 - it would be nice to have a "Community Prop" that = could be used as a relative calibration point. I know if this prop swap = had happened 3 months earlier, Sam would have been even happier {:>) One thing that can give you a reality check is your fuel flow rate at = 6100 rpm - to be producing 196 HP, your fuel flow rate should be around = 19-20 GPH. So unless your fuel flow rate is in that vicinity, its = unlikely you are producing 196 HP - although, I would hazard a SWAG that = that you may be close to 180 HP. =20 A fuel burn rate for the rotary (rule of thumb) is that it take around = 10 GPH flow rate to produce 100 HP. So if your flow rate is say 15-16 = GPH you are probably in the vicinity of 150-160 HP. However, the rotary = has shown the ability to flow more fuel than it can use to produce = useful power. So a higher flow rate does not necessarily all translate = into power, but lacking a portable dyno it's a place to start. Ed From: Jeff Whaley=20 Sent: Friday, October 08, 2010 8:41 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Another prop performance calculator Ed, with my prop numbers (74"x 58", 4 blades, 59F, 6100 engine rpm or = 2140 prop rpm) entered into this calculator it says I'm making 196 hp = static ... seems hard to believe. I've always wondered what the difference is between 4 blades Vs 2 ... = the same numbers with 2 blades gives 117 hp.. Also, my prop is a Warp Drive and the pitch is measured at the tip ... = don't most prop manufacturers specify pitch at 75-80% of diameter? Wish I had been in Paducah to bolt your prop on and see what happened = ... Jeff From: "Ed Anderson" =20 Subject: Another Prop Performance Calculator=20 Date: Fri, 8 Oct 2010 19:06:16 -0400=20 To: "Rotary motors in aircraft" = =20 =20 =20 =20 Here is a link to a STATIC performance calculator that seems to at = least give reasonable results http://personal.osi.hu/fuzesisz/strc_eng/index.htm I could turn 5800 rpm static when my prop was 76x88 which this = calculator indicates the engine was producing 168.1 HP to turn the prop = 2035 rpm When I trimmed the prop back to 74x88 I picked up 200 static = engine rpm which this calculator then indicated the engine was = producing167.2 HP to turn the prop 2105 rpm So between 165 and 170 HP seems reasonable. Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 http://www.andersonee.com http://www.eicommander.com =20 This message, and the documents attached hereto, is intended only for = the addressee and may contain privileged or confidential information. = Any unauthorized disclosure is strictly prohibited. If you have received = this message in error, please notify us immediately so that we may = correct our internal records. Please then delete the original message. = Thank you. ------=_NextPart_000_000D_01CB6738.BC36D250 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Jeff, Wish I knew something about props, but it = seems more=20 black art than cooling ducts {:>).  Having 4 blades with a 74" = dia and=20 spinning 6100 rpm even with 58" pitch would appear to me to indicate a = strong=20 engine.  But, you are right, its really hard to compare apples and=20 oranges.
 
We clearly saw a significant difference in = performance=20 between Sam's prop and mine - on his engine.  Sam was clearly = delighted to=20 be producing over 6000 - it would be nice to have a "Community Prop" = that could=20 be used as a relative calibration point.  I know if this prop swap = had=20 happened 3 months earlier, Sam would have been even happier = {:>)
 
One thing that can give you a reality check is = your fuel=20 flow rate at 6100 rpm - to be producing 196 HP, your fuel flow rate = should be=20 around 19-20 GPH.  So unless your fuel flow rate is in that = vicinity, its=20 unlikely you are producing 196 HP - although, I would hazard a SWAG that = that=20 you may be close to 180 HP. 
 
A fuel burn rate for the rotary (rule of thumb) = is that it=20 take around 10 GPH flow rate to produce 100 HP.  So if your flow = rate is=20 say 15-16 GPH you are probably in the vicinity of 150-160 HP.  = However, the=20 rotary has shown the ability to flow more fuel than it can  use to = produce=20 useful power.  So a higher flow rate does not necessarily all = translate=20 into power, but lacking a portable dyno it=92s a place to = start.
 
Ed

From: Jeff Whaley
Sent: Friday, October 08, 2010 8:41 PM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Another prop performance=20 calculator

Ed, with my prop=20 numbers (74"x 58", 4 blades, 59F, 6100 engine rpm or 2140 prop rpm) = entered into=20 this calculator it says I'm making 196 hp static ... seems hard to=20 believe.
I've always wondered what = the difference=20 is between 4 blades Vs 2 ... the same numbers with 2 blades gives 117=20 hp..
Also, my prop is a Warp = Drive and the=20 pitch is measured at the tip ... don't most prop manufacturers specify = pitch at=20 75-80% of diameter?
Wish I had been in Paducah = to bolt your=20 prop on and see what happened ...
Jeff
 
 
=
From: "Ed Anderson"=20 <eanderson@carolina.rr.com>
Subject: Another Prop Performance=20 Calculator
Date: Fri, 8 Oct 2010 19:06:16 = -0400
To: "Rotary motors in aircraft"=20 = <flyrotary@lancaironline.net>
 3D"Message

3D"Undecoded=20
Here is a link to a STATIC performance = calculator=20 that seems to at least give reasonable results
 
http://personal.osi.hu/fuzesisz/strc_eng/index.htm
 
I could turn 5800 rpm static when my prop = was 76x88=20 which this calculator indicates the engine was producing 168.1 HP = to turn=20 the prop 2035 rpm
 
When I trimmed the prop back to 74x88 I = picked up=20 200 static  engine rpm which this calculator then indicated = the=20 engine was producing167.2 HP to turn the prop 2105 = rpm
 
So between 165 and 170 HP seems=20 reasonable.
 
 
 
Edward L. Anderson
Anderson Electronic=20 Enterprises LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com

This message, and the documents = attached hereto,=20 is intended only for the addressee and may contain privileged or = confidential=20 information. Any unauthorized disclosure is strictly prohibited. If you = have=20 received this message in error, please notify us immediately so that we = may=20 correct our internal records. Please then delete the original message. = Thank=20 you.
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