X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-bk0-f42.google.com ([209.85.214.42] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6507177 for flyrotary@lancaironline.net; Tue, 08 Oct 2013 14:24:50 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.214.42; envelope-from=msteitle@gmail.com Received: by mail-bk0-f42.google.com with SMTP id my10so3401878bkb.15 for ; Tue, 08 Oct 2013 11:24:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=R99IXLvMvCaP4DK/yjsCvIqfWbatCVQhvNixOvR5uiE=; b=CNQkC21jICSCEY2C0fK6H10WnMnt5w0ZfoHYcjkb1GvkctCRa3vngG3PFb9iiKl04k dWtOX1f+jhZkpdKuuAo6jxcX/DPwi5E6Cebu33jtGdVXetZrJPOG1VtiLAGuKxH0Gb8r C6muAoWjbYVyuRqmMI2mvhMCiVkrcpBK9NVP/ZwfF7zIso9k/iD7ddEXmPHv0ZAzz9U1 AdCcMkaLKpnH93mYIGdQcqZRXbhvQHt45YLCbQ2/1jlSOVwciW/T0gM3kclPoaONyKxL Gh2NCSagP/gE0iUZwYiPac0ATepTCOQoG8jdQM0KTxkGjuzykmo+3sn7k2xdOm/jp4Ia Y94g== MIME-Version: 1.0 X-Received: by 10.204.121.201 with SMTP id i9mr2982213bkr.13.1381256656504; Tue, 08 Oct 2013 11:24:16 -0700 (PDT) Received: by 10.204.102.195 with HTTP; Tue, 8 Oct 2013 11:24:16 -0700 (PDT) In-Reply-To: References: Date: Tue, 8 Oct 2013 13:24:16 -0500 Message-ID: Subject: Re: [FlyRotary] Re: Prop and PSRU efficiency From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=001a1133494e5af85904e83ee008 --001a1133494e5af85904e83ee008 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Bill, Sounds pretty much like what I've done with my 3-rotor. My initial side-port 20b with MT 3-blade electric prop, WOT with prop set to 1700, resulted in a TAS of 159 kts. The new p-port engine would true out at 183 kts with the same settings. I guess I could calculate the added hp if I knew the flat plate area of the airframe. But I'm happy just to be going faster than I was before the upgrade. My point with the HP calculation was that if we're going to come up with a horsepower number, it won't be long and someone will compare those HP numbers to a Lycoming of some configuration. While I'm pretty sure that Lycoming doesn't test their engines with a water pump connected, I was wondering if they include an alternator, air cleaner, stock exhaust, etc. in the calculation? And what other "tricks" do they use to get to their magic HP numbers? Mark On Tue, Oct 8, 2013 at 1:00 PM, Bill Bradburry wr= ote: > ** ** ** ** > > Mark,**** > > ** ** > > I think I may be trying to determine =93SAE Kentucky Windage HP=94! :>)*= *** > > ** ** > > To do this test I would have to estimate the exact weight of the plane at > the time of the test, estimate the density altitude and all the things th= at > go into figuring it out, estimate what the climb rate really was, estimat= e > what the descent rate really was, estimate prop efficiency, estimate the > PSRU losses, etc=85the only =93known=94 number I would be working with in= the > calculation is the number 33000. **** > > ** ** > > I have been telling myself, =93Self! I don=92t think my engine is really = hairy > chested like I wanted it to be!=94**** > > ** ** > > I plan to get an estimated descent rate and climb rate, run it thru this > calculation and see if I still feel this way. :>)**** > > ** ** > > If it turns out to be accurate, I plan to stay away from dark clouds due > to fear of being struck by lightening! :>)**** > > ** ** > > Bill B**** > ------------------------------ > > *From:* **Rotary motors in aircraft** [mailto:flyrotary@lancaironline.net= ] > *On Behalf Of *Mark Steitle > *Sent:* Monday, October 07, 2013 8:24 PM > *To:* **Rotary motors in aircraft** > *Subject:* [FlyRotary] Re: Prop and PSRU efficiency**** > > ** ** > > Bill, **** > > ** ** > > I was getting at a defined standard so that your numbers could be compare= d > to a certified a/c engine. Wikipedia defines SAE hp, depending on the > configuration of the engine being tested, as follows:**** > > ** ** > *SAE gross power*[edit > ]**** > > Prior to the 1972 model year, American automakers rated and advertised > their engines in brake horsepower (bhp), frequently referred to as SAE > gross horsepower, because it was measured in accord with the protocols > defined in SAEstandards > J245 and J1995. As with other brake horsepower test protocols, SAE gross = hp > was measured using a stock test engine, generally running with few > belt-driven accessories and sometimes fitted with long tube test headers<= http://en.wikipedia.org/wiki/Exhaust_manifold> in > lieu of the OEM exhaust > manifolds. The atmospheric correction standards for barometric pressure, > humidity and temperature for testing were relatively idealistic.**** > *SAE net power*[edit > ]**** > > In the ****United States****, the term *bhp* fell into disuse in 1971-72, > as automakers began to quote power in terms of SAE net horsepower in acco= rd > with SAE standard J1349. Like SAE gross and other brake horsepower > protocols, SAE Net hp is measured at the engine's crankshaft, and so does > not account for transmission losses. However, the SAE net power testing > protocol calls for standard production-type belt-driven accessories, air > cleaner, emission controls, exhaust system, and other power-consuming > accessories. This produces ratings in closer alignment with the power > produced by the engine as it is actually configured and sold.**** > *SAE certified power*[edit > ]**** > > In 2005, the SAE introduced "SAE Certified Power" with SAE J2723.[20] This > test is voluntary and is in itself not a separate engine test code but a > certification of either J1349 or J1995 after which the manufacturer is > allowed to advertise "Certified to SAE J1349" or "Certified to SAE J1995" > depending on which test standard have been followed. To attain > certification the test must follow the SAE standard in question, take pla= ce > in an ISO9000/9002 certified facility and be witnessed by an SAE approved > third party.**** > > ** ** > > So, if I understand you correctly, you are looking to determine "SAE Net > HP", which is measured at the flywheel, and includes air filter, > accessories, stock exhaust, etc. Without these "additions", you would be > talking "SAE Gross HP". **** > > ** ** > > Mark**** > > ** ** > > On Mon, Oct 7, 2013 at 4:42 PM, **Bill Bradburry **< > bbradburry@bellsouth.net> wrote:**** > > Based on the below statement, where would ****Tracy****=92s planet gear > system fall?**** > > **** > > PSRUs have losses inherent in their gearsets or belts. Lay people have > often speculated that these losses are up to 40 hp in the case of a 200 h= p > class drive. This is absurd as it would represent about 30,000 watts bein= g > dissipated as heat. If this was in fact true, the case or belts would mel= t > in just a few minutes. Typical losses for single mesh spur and helical > gears is around 2-2.5%. HTD belts run at 3-4%. Twin mesh helical gearsets > would then have perhaps a 6% loss as worst case including bearing losses.= * > *** > > The statement came from:**** > > **** > > http://www.sdsefi.com/air51.htm**** > > **** > > B2**** > > **** > ------------------------------ > > *From:* **Rotary motors in aircraft** [mailto:flyrotary@lancaironline.net= ] > *On Behalf Of *Bill Bradburry > *Sent:* Monday, October 07, 2013 3:42 PM > *To:* **Rotary motors in aircraft** > *Subject:* [FlyRotary] Re: Prop and PSRU efficiency**** > > **** > > Mark,**** > > **** > > They would be included if the engine was tested on a dyno, so I consider > them to be part of the engine. But not so the PSRU if measuring from the > flywheel.**** > > **** > > Ernest,**** > > **** > > I don=92t know what you mean by .98 to .99?? Certainly you don=92t think= it > would only be a loss of 1 or 2%!?? It would have to be in the range of 1= 0 > to 20 HP or even greater. That is 5 to 10% in our HP range. Just the lo= ss > due to prop efficiency is in the range of 30 HP!**** > > **** > > Bill **** > > **** > ------------------------------ > > *From:* **Rotary motors in aircraft** [mailto:flyrotary@lancaironline.net= ] > *On Behalf Of *Mark Steitle > *Sent:* Monday, October 07, 2013 1:26 PM > *To:* **Rotary motors in aircraft** > *Subject:* [FlyRotary] Re: Prop and PSRU efficiency**** > > **** > > Bill, **** > > **** > > While you're at it don't forget to account for the water pump and > alternator(s). **** > > **** > > Mark S.**** > > **** > > On Mon, Oct 7, 2013 at 12:18 PM, **Bill Bradburry **< > bbradburry@bellsouth.net> wrote:**** > > I have asked this question a couple of times and no one has hazarded a > guess. > > How much HP is lost from our engines due to the PSRU? I have been > interested in determining what the HP output of my engine is and that inf= o > would be needed for that estimation. > > They tell me that most props are about 80-85% efficient, so to calculate > the > hp, you take the difference between your climb rate and your glide descen= t > rate at the same airspeed, multiplied by the weight, and then divided by > 33000. > > Wt * V / 33000 =3D HP > > This would be the prop HP, so to get the prop flange HP, you would divide > by > the prop efficiency, between .8 and .85. > > To get the engine flywheel HP, you would have to add something for the lo= ss > of the PSRU. > > Is anyone willing to take a shot at that number?? Third or forth chance! > :>) > > Bill B > > > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html**** > > **** > > ** ** > --001a1133494e5af85904e83ee008 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
Bill,
=A0
Sounds pretty much lik= e what I've done with my 3-rotor.=A0 My initial side-port 20b with MT 3= -blade electric prop, WOT with prop set to 1700, resulted in a TAS of 159 k= ts.=A0 The new p-port engine would true out at 183 kts with the same settin= gs.=A0 I guess I could calculate the added hp if I knew the flat plate area= of the airframe.=A0 But I'm happy just=A0to be going faster than I was= before the upgrade.=A0
=A0
My point with the HP calculation was that if we're g= oing to come up with a horsepower number, it won't be long and someone = will compare=A0those=A0HP numbers=A0to a Lycoming of some configuration.=A0= While I'm pretty sure that Lycoming doesn't test their engines wit= h a water pump connected, I was wondering if they=A0include an=A0alternator= , air cleaner, stock exhaust, etc.=A0in the calculation?=A0 And what other = "tricks" do they use to get to their magic=A0HP numbers?=A0=A0=A0=
=A0
Mark


On Tue, Oct 8, 2013 at 1:00 PM, Bill Bradburry <bbradburry@bellsouth.net> wrote:

Mark,

=A0=

I think I may be trying to dete= rmine =93SAE Kentucky Windage HP=94!=A0 :>)

=A0=

To do this test I would have to= estimate the exact weight of the plane at the time of the test, estimate the density altitude and all the things that go into figuring it out, estimate what the climb rate really was, estimate what the descent rate really was, estimate = prop efficiency, estimate the PSRU losses, etc=85the only =93known=94 number I would be working with in the calculation is the number 33000. <= /u>

=A0=

I have been telling myself, =93= Self! I don=92t think my engine is really hairy chested like I wanted it to be!=94<= u>

=A0=

I plan to get an estimated desc= ent rate and climb rate, run it thru this calculation and see if I still feel this way.=A0 :>)

=A0=

If it turns out to be accurate,= I plan to stay away from dark clouds due to fear of being struck by lightening!=A0 :&= gt;)

=A0=

Bill B

From: Rotar= y motors in aircraft [mailto:fl= yrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Monday, October 07, 20= 13 8:24 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Pro= p and PSRU efficiency

=A0

Bill,=A0

=A0

I was getting at a defined standard so that your numbe= rs could be compared to a certified a/c engine. =A0Wikipedia defines SAE hp, depending on the configuration of the engine being tested, as follows:<= /span>

=A0

SAE gross power[edit]

Prior to the 1972 model year, American automakers rated and advertised their engines in brake horsepower (bhp), frequently referred to as SAE gross horsepower, because i= t was measured in accord with the protocols defined in=A0SAEstandard= s J245 and J1995. As with other brake horsepower test protocols, SAE gross hp was measured using a stock test engine, generally running with few belt-driven accessories and sometimes fitted with long tube test=A0headers=A0in lieu of the=A0OEM=A0exhaust manifolds. The atmospheric correction standards for barometric pressure, humidity and temperature for testing were relatively idealistic.<= /u>

SAE net power<= /span>[edit]

In the United States, the term=A0bhp=A0fell into disuse in 1971-72, as automakers began to quote power in terms of SAE net horsepower in accord with SAE standard J1349. Like SAE gross and other brak= e horsepower protocols, SAE Net hp is measured at the engine's crankshaft= , and so does not account for transmission losses. However, the SAE net power testin= g protocol calls for standard production-type belt-driven accessories, air cleaner, emission controls, exhaust system, and other power-consuming accessories. This produces ratings in closer alignment with the power produ= ced by the engine as it is actually configured and sold.

SAE certified = power[edit]

In 2005, the SAE introduced "SAE Certified Power" with SAE J2723.[20]=A0This test is voluntary and is in itself not a separate engine test code but a certification of either J1349 or J1995 after which the manufacturer is allo= wed to advertise "Certified to SAE J1349" or "Certified to SAE J1995" depending on which test standard have been followed. To attain certification the test must follow the SAE standard in question, take place= in an ISO9000/9002 certified facility and be witnessed by an SAE approved thir= d party.

=A0

So, if I understand you correctly, you are looking to determine "SAE Net HP", which is measured at the flywheel, and includes air filter, accessories, stock exhau= st, etc. =A0Without these "additions", you would be talking "SAE Gross HP". =A0

=A0

Mark

=A0<= /font>

On Mon, Oct 7, 2013 at 4:42 PM, Bill Bradburry <bbradburry@bellsouth.net> wrote:

Based on the below statement, w= here would Tracy=92s planet gear system fall?

=A0=

PSRUs have losses inherent in their gearsets or belts. Lay people have often speculated that these losses are up to 40 hp in the case of a 200 hp class drive. This is absurd as it would represent about 30,000 watts being dissip= ated as heat. If this was in fact true, the case or belts would melt in just a f= ew minutes. Typical losses for single mesh spur and helical gears is around 2-2.5%. HTD belts run at 3-4%. Twin mesh helical gearsets would then have perhaps a 6% loss as worst case including bearing losses.

The statement came from:=

=A0=

http://www.sdsefi.com/air51.htm

=A0=

B2<= /p>

=A0=

From: Rotar= y motors in aircraft [mailto:fl= yrotary@lancaironline.net] On Behalf Of Bill Bradburry<= br> Sent: Monday, October 07, 20= 13 3:42 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Pro= p and PSRU efficiency

=A0

Mark,

=A0=

They would be included if the e= ngine was tested on a dyno, so I consider them to be part of the engine.=A0 But not so the PSRU if measuring from the flywheel.

=A0=

Ernest,=

=A0=

I don=92t know what you mean by= .98 to .99??=A0 Certainly you don=92t think it would only be a loss of 1 or 2%!??=A0 It would have to be in the range of 10 to 20 HP or even greater.=A0 That is 5 to 10% in our HP range.=A0 Just the loss due to prop efficiency is in the range of 30 HP!

=A0=

Bill

=A0=

From: Rotar= y motors in aircraft [mailto:fl= yrotary@lancaironline.net] On Behalf Of Mark Steitle Sent: Monday, October 07, 20= 13 1:26 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Pro= p and PSRU efficiency

=A0

Bill,

=A0

While you're at it don't forget to account for the water pump and alternator(s).

=A0

Mark S.

=A0<= /font>

On Mon, Oct 7, 2013 at 12:18 PM, Bill Bradburry <bbradburry@bellsouth.net> wrote:

I have asked this question a couple of times and no one has hazarded a
guess.

How much HP is lost from our engines due to the PSRU? =A0I have been
interested in determining what the HP output of my engine is and that info<= br> would be needed for that estimation.

They tell me that most props are about 80-85% efficient, so to calculate th= e
hp, you take the difference between your climb rate and your glide descent<= br> rate at the same airspeed, multiplied by the weight, and then divided by 33000.

Wt * V / 33000 =3D HP

This would be the prop HP, so to get the prop flange HP, you would divide b= y
the prop efficiency, between .8 and .85.

To get the engine flywheel HP, you would have to add something for the loss=
of the PSRU.

Is anyone willing to take a shot at that number?? =A0Third or forth chance!=
:>)

Bill B




--
Homepage: =A0http:/= /www.flyrotary.com/
Archive and UnSub: =A0 http://mail.lancaironline.net:81/lists= /flyrotary/List.html

=A0

=A0


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