X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost03.isp.att.net ([207.115.11.53] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTP id 6511350 for flyrotary@lancaironline.net; Fri, 11 Oct 2013 09:03:51 -0400 Received-SPF: none receiver=logan.com; client-ip=207.115.11.53; envelope-from=bbradburry@bellsouth.net Received: from desktop (adsl-98-85-147-248.mco.bellsouth.net[98.85.147.248]) by isp.att.net (frfwmhc03) with SMTP id <20131011130313H0300pnd34e>; Fri, 11 Oct 2013 13:03:13 +0000 X-Originating-IP: [98.85.147.248] From: "Bill Bradburry" To: "'Rotary motors in aircraft'" References: In-Reply-To: Subject: RE: [FlyRotary] Re: Prop and PSRU efficiency Date: Fri, 11 Oct 2013 09:03:20 -0400 Message-ID: <378C0961335D4CCA8678F8080BC54F64@Desktop> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004C_01CEC660.BC1B0310" X-Mailer: Microsoft Office Outlook 11 Thread-Index: Ac7GgJuptzoyehk1SU2gVo9a3Eq4HAAAKMJw X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18463 This is a multi-part message in MIME format. ------=_NextPart_000_004C_01CEC660.BC1B0310 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Crap! Can't you taxi over to San Marcos? It is only a couple of miles from Lockhart! :>) The rule is that the plane get there under its own power.doesn't say you have to fly there. B2 _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle Sent: Friday, October 11, 2013 8:51 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Prop and PSRU efficiency Bill, I was planning on flying, but it has gone MVFR and IFR all over the area with rain predicted today and through the weekend. It doesn't look very promising at this time. ;-( Mark On Fri, Oct 11, 2013 at 7:23 AM, Bill Bradburry wrote: When you get back in the air with your new panel you will have to share some performance numbers with us. HP is just a number, what counts is what the airplane does in speed, climb rate, and fuel burn. And most important, satisfaction with those performance numbers! :>) Are you flying this weekend? You gotta take advantage of that buck gas! A tank of that will buy you a set of plugs if need be! :>) B2 _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle Sent: Friday, October 11, 2013 6:21 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Prop and PSRU efficiency It's much too late for that now. Guess I will have to settle on the data from other sources when it comes to the hp figures for the p-port engines until I have the opportunity to dyno it. My original goal was to be able to cruise at 200 mph, which the side port engine couldn't quite do. The p-port engine hits 200 with ease. Life is good! Mark Sent from my iPad On Oct 8, 2013, at 1:35 PM, "Bill Bradburry" wrote: Mark, If you happened to record your climb rate and weight with the old configuration, you could duplicate a climb rate at the same weight with the new configuration, then using that formula and plugging in the difference in climb rate, you could get pretty darn close to the increase in HP due to the new configuration. Bill B _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle Sent: Tuesday, October 08, 2013 2:24 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Prop and PSRU efficiency 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 wrote: Mark, I think I may be trying to determine "SAE Kentucky Windage HP"! :>) 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.the only "known" number I would be working with in the calculation is the number 33000. I have been telling myself, "Self! I don't think my engine is really hairy chested like I wanted it to be!" 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 compared 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 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 accord 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 place 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 wrote: Based on the below statement, where would Tracy's 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 hp class drive. This is absurd as it would represent about 30,000 watts being dissipated as heat. If this was in fact true, the case or belts would melt 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't know what you mean by .98 to .99?? Certainly you don't think it would only be a loss of 1 or 2%!?? It would have to be in the range of 10 to 20 HP or even greater. That is 5 to 10% in our HP range. Just the loss 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 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 info 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 descent rate at the same airspeed, multiplied by the weight, and then divided by 33000. Wt * V / 33000 = 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 loss 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 ------=_NextPart_000_004C_01CEC660.BC1B0310 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Crap!  Can’t you taxi = over to San = Marcos?  It is only a couple of miles from Lockhart!  = :>)

 

The rule is that the plane get = there under its own power…doesn’t say you have to fly = there.

 

B2

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Friday, October 11, = 2013 8:51 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Prop and PSRU efficiency

 

Bill, =

I was planning = on flying, but it has gone MVFR and IFR all over the area with rain predicted today = and through the weekend.  It doesn't look very promising at this = time.  ;-(

Mark

 

On Fri, Oct 11, 2013 at 7:23 AM, Bill Bradburry <bbradburry@bellsouth.net> = wrote:

When you get back in the air with your new panel you will = have to share some performance numbers with us.  HP is just a number, what = counts is what the airplane does in speed, climb rate, and fuel burn.  And = most important, satisfaction with those performance numbers!  = :>)

 

Are you flying this weekend?  You gotta take advantage = of that buck gas!  A tank of that will buy you a set of plugs if need = be!  :>)

 

B2

 

From: Rotary motors in = aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark = Steitle
Sent: Friday, October 11, = 2013 6:21 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Prop and PSRU efficiency

 

It's = much too late for that now.  Guess I will have to settle on the data from other = sources when it comes to the hp figures for the p-port engines until I have the opportunity to dyno it. 

 

My = original goal was to be able to cruise at 200 mph, which the side port engine couldn't = quite do.  The p-port engine hits 200 with ease.  Life is = good!

 

Mark

Sent from my iPad


On Oct 8, 2013, at 1:35 PM, "Bill Bradburry" <bbradburry@bellsouth.net> wrote:

Mark,

If you happened to record your climb rate and weight with = the old configuration, you could duplicate a climb rate at the same weight with = the new configuration, then using that formula and plugging in the difference in = climb rate, you could get pretty darn close to the increase in HP due to the = new configuration.

 

Bill B

 

From: Rotary motors in = aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark = Steitle
Sent: Tuesday, October = 08, 2013 2:24 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Prop and PSRU efficiency

 

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 = <bbradburry@bellsouth.net> wrote:

Mark,

 

I think I may be trying to determine “SAE Kentucky = Windage HP”!  :>)

 

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…the only “known” number I would be working = with in the calculation is the number 33000.

 

I have been telling myself, “Self! I don’t think = my engine is really hairy chested like I wanted it to = be!”

 

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 compared 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 SAEstandar= ds 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 in lieu of = the OEM e= xhaust 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 accord 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 = place 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’s 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 hp = class drive. This is absurd as it would represent about 30,000 watts being = dissipated as heat. If this was in fact true, the case or belts would melt 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<= /o:p>

 

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’t know what you mean by .98 to .99??  = Certainly you don’t think it would only be a loss of 1 or 2%!??  It = would have to be in the range of 10 to 20 HP or even greater.  That is 5 to = 10% in our HP range.  Just the loss 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 = info
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 = descent
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 = loss
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.h= tml

 

 

 

 

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