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 5.3.7) with ESMTP id 4315327 for flyrotary@lancaironline.net; Sat, 15 May 2010 07:22:47 -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=6d7Ts9tzjFwCYLvIP9YziGU0x6Z20c+JxtSyo0GTZmg= c=1 sm=0 a=HsYLC217TCIA:10 a=UBIxAjGgU1YA:10 a=Er6hwA6a1l4K/FyzC6NN7w==:17 a=ayC55rCoAAAA:8 a=arxwEM4EAAAA:8 a=QdXCYpuVAAAA:8 a=7g1VtSJxAAAA:8 a=ekHE3smAAAAA:20 a=UretUmmEAAAA:8 a=Ia-xEzejAAAA:8 a=C_IRinGWAAAA:8 a=kviXuzpPAAAA:8 a=_FjZcMbStKdBftUcaeUA:9 a=LNGKLXi--tZTZf7tXIAA:7 a=hTZerda7cZzipln0jCaJjGqDqqwA:4 a=CjuIK1q_8ugA:10 a=1vhyWl4Y8LcA:10 a=EzXvWhQp4_cA:10 a=si9q_4b84H0A:10 a=4vB-4DCPJfMA:10 a=naRnGXQWR3rw5DTN:21 a=n3tU1Jvoo6yPBMIw:21 a=SSmOFEACAAAA:8 a=quNswNU0fWdG8YBGhNwA:7 a=_eKiP9qCtkANUeRzYpBQtpySBl0A:4 a=yrxdWiPvZos2Lzqi:21 a=5RiZ6RsTOTiOeKck:21 a=Er6hwA6a1l4K/FyzC6NN7w==:117 X-Cloudmark-Score: 0 X-Originating-IP: 75.181.123.159 Received: from [75.181.123.159] ([75.181.123.159:4245] helo=computername) by cdptpa-oedge03.mail.rr.com (envelope-from ) (ecelerity 2.2.2.39 r()) with ESMTP id E2/46-20538-2E38EEB4; Sat, 15 May 2010 11:22:11 +0000 From: "Ed Anderson" Message-ID: To: "'Rotary motors in aircraft'" Subject: flyin vs Babe was [FlyRotary] Re: alternative water pump Date: Sat, 15 May 2010 07:21:53 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0021_01CAF3FF.4B514DB0" X-Mailer: Microsoft Office Outlook, Build 11.0.5510 In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5931 Thread-Index: Acr0FgL7IBxik+ApRkuPePW2iRTd+AACowZw This is a multi-part message in MIME format. ------=_NextPart_000_0021_01CAF3FF.4B514DB0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hey, I mean deciding between a fly-in and spending days in the Colorado isolation with a California Babe - and you choose the Babe???? Good Choice!!!! Enjoy, Tracy, but do come back. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy Crook Sent: Saturday, May 15, 2010 6:04 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: alternative water pump I also measure the temperature at the engine, on the block where the coolant has gone 1/2 way through the engine on the hot side. It registers somewhat higher, but that should be expected. I found that same thing on the 2nd gen 13B Bill. The coolant temp actually drops a little on its trip past the 'cool' side of the engine. The same is not true on the Renesis due to the heating from the side exhaust passages. Was really looking forward to being at the mid Atlantic fly-in with the RV-8 but such is fate. My California girl friend's vacation coincides with those dates so I'll be spending it with her in Colorado Tracy On Fri, May 14, 2010 at 11:00 PM, Bill Schertz wrote: Ed, I went with parallel cores to maximize the flow through the engine, and to keep the pressure drop as low as possible. Interestingly, I have a thermocouple on the inlet to the cores, and one on the exit to the cores. They show a ~5*F temperature drop across the cores. I also measure the temperature at the engine, on the block where the coolant has gone 1/2 way through the engine on the hot side. It registers somewhat higher, but that should be expected. Bill Schertz KIS Cruiser #4045 N343BS Phase I testing From: Ed Anderson Sent: Friday, May 14, 2010 5:32 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: alternative water pump Hi Bill, Had seen your nice data before, but one thing finally awoke in my old brain when I looked at it this time that I had not considered before. We know that parallel cores give slightly better efficiency than a serial core set because the DT decreases for the second core in the series compared to both parallel cores having the same DT (at least in theory). However, what jumped out at me this time was the real significance of the parallel cores in cooling. In this case, I am assuming no thermostat in the coolant flow. If I understood your graphs correctly, it looks like you are getting around 20 gpm flow with a single core (so presumably you would get a bit less with two cores in series - but perhaps not significantly), but looks like with parallel cores you are getting around 32 gpm flow. That is a 20/32 = approx 37 % more mass coolant flow through the engine. That means (all else being equal), you should transfer 37% more heat out of the engine per unit time with the parallel cores compared to the serial cores (assuming cores of same type and size). Now the engine is producing X amount of waste heat at Y HP that it needs to get rid of. That won't change for a given power setting Y. So Q (waste heat X) produced by the engine should be a constant at Y Hp. So taking Q = M*Dt/Cp and since Q (waste heat) = constant at power setting Y, then with M (mass flow up 37%) implies that in this case Dt = (Temp of coolant out of engine - temp of coolant into engine) should decrease by 37%. When you increase the mass flow and are removing the same quantity of heat, the DT is of necessity a lower value. If that is the case, then the question is - does this mean the temp of coolant into the engine increases - not necessarily desirable, or does the Temp of coolant out of the engine decrease? Or a bit of both? I suspect it's a bit of both depending on the radiator's performance. If your radiators/air flow are the limiting factors, then transferring more heat per unit time to the radiators is not going to buy you much. The reason is that if it is not able to get rid of the heat at the faster rate and the DT between the coolant and air will be less. But, my guess is that this theoretical increase in heat removal by using parallel cores could be useful in some situations - again if you are already limited in the airflow situation, then this won't make much difference. It does suggest that using parallel cores could result in the need for core sizes 37% smaller. OR did I miss something here? Like your data in any case Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bill Schertz Sent: Thursday, May 13, 2010 10:39 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: alternative water pump Back in 2002 I measured the flow from a 13-B pump, attached to the engine but driven with an electric motor. The curve is attached. I ran the pump at 3 different RPM, established by changing the pulley size on the motor. At 5594 rpm, the pump produced 19 psi at zero flow, and 44 gpm at 0 psi. At lower RPM, the pump of course pumps less. The other test I did was to measure the flow through one core of the two I was using for my installation. That is the curve going up to the right with the red dots as the experimental points. Since I am running my cores in parallel, the right hand rising curve is a 'calculated' flow response for the parallel cores. Finally, I hooked up the cores to the system, and pumped water through them. The single large point represents where the flow and pressure came out, very close to the calculated expected response. All flow measurements were done by the "bucket and stop-watch" technique, with multiple runs to get the flow. Bill Schertz KIS Cruiser #4045 N343BS Phase I testing From: Al Gietzen Sent: Wednesday, May 12, 2010 11:54 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: alternative water pump Al, Are you sure of the 40 GPM? That seems like a lot. My radiator in/out is 1.25 inches, so the water would be traveling at 628 feet per minute at that flow rate. That is over 7 miles per hour! Bill B When my 20B (with a 13B pump that Atkins referred to as 'high flow') was on the dyno the measured flow was 48 gpm with the standard pulleys. I expect the dyno cooling loop was fairly low pressure drop compared to our typical systems, so I'm just guessing 40 gpm is in the ballpark. 628 fpm (10.5 ft/sec) would not be considered very high - - above 15 ft/sec I'd consider high. Al ------=_NextPart_000_0021_01CAF3FF.4B514DB0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Hey, I mean deciding between a = fly-in and spending days in the Colorado isolation with a California Babe – and you choose the = Babe????  Good Choice!!!!

 

Enjoy, Tracy, but do come = back.

 

Ed

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy Crook
Sent: Saturday, May 15, = 2010 6:04 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: alternative water pump

 

I also measure the temperature at = the engine, on the block where the coolant has gone 1/2 way through the = engine on the hot side. It registers somewhat higher, but that should be = expected.

 

I found that = same thing on the 2nd gen 13B Bill.  The coolant temp actually drops a little = on its trip past the 'cool' side of the engine.  The same is not true on = the Renesis due to the heating from the side exhaust passages.

Was really looking forward to being at the mid Atlantic fly-in with the = RV-8 but such is fate.  My California = girl friend's vacation coincides with those dates so I'll be spending it with = her in Colorado

Tracy

On Fri, May 14, 2010 at 11:00 PM, Bill Schertz <wschertz@comcast.net> = wrote:

Ed,

I went with parallel cores to maximize the flow = through the engine, and to keep the pressure drop as low as = possible.

 

Interestingly, I have a thermocouple on the inlet to = the cores, and one on the exit to the cores. They show a ~5*F temperature = drop across the cores. I also measure the temperature at the engine, on the = block where the coolant has gone 1/2 way through the engine on the hot side. = It registers somewhat higher, but that should be = expected.

 

 

Bill Schertz
KIS Cruiser #4045
N343BS
Phase I testing

 

From: Ed Anderson =

Sent: Friday, May 14, 2010 5:32 PM

Subject: [FlyRotary] Re: alternative water pump

 

Hi Bill,

 

Had seen your nice data before, but one thing finally awoke = in my old brain when I looked at it this time that I had not considered = before.  We know that parallel cores give slightly better efficiency than a = serial core set because the D<= font size=3D2 color=3Dnavy face=3DArial>T decreases for the second core in the series compared to = both parallel cores having the same D<= font size=3D2 color=3Dnavy face=3DArial>T (at least in theory).  However, what jumped out at me = this time was the real significance of the parallel cores in cooling.  = In this case, I am assuming no thermostat in the coolant = flow.

 

If I understood your graphs correctly, it looks like you are getting around 20 gpm flow with a single core (so presumably you would = get a bit less with two cores in series – but perhaps not = significantly), but looks like with parallel cores you are getting around 32 gpm flow.  That = is a 20/32 =3D  approx 37 %  more mass coolant flow through the engine.   That means (all else being equal), you should = transfer 37% more heat out of the engine per unit time with the parallel cores = compared to the serial cores (assuming cores of same type and size).  =

 

Now the engine is producing X amount of waste heat at Y HP = that it needs to get rid of.  That won’t change for a given power = setting Y.  So Q (waste heat X) produced by the  engine should be a constant at = Y Hp.

 

So taking Q =3D M*D<= font size=3D2 color=3Dnavy face=3DArial>t/Cp and since Q (waste heat)  =3D constant at power = setting Y, then with M (mass flow up 37%)  implies that in this case = Dt =3D (Temp of = coolant out of engine – temp of coolant into engine)  should decrease by = 37%.  When you increase the mass flow and are removing the same quantity of = heat, the DT is of necessity a lower value.

 

If that is the case, then the question is  - does this = mean the temp of coolant into = the engine increases – = not necessarily desirable, or does the Temp of coolant out of the engine decrease? Or a = bit of both?  I suspect it’s a bit of both depending on the = radiator’s performance.  If your radiators/air flow are the limiting factors, = then transferring more heat per unit time to the radiators is not going to = buy you much.  The reason is that if it is not able to get rid of the heat = at the faster rate and the DT between the coolant and air will be less. =

 

But, my guess is that this theoretical increase in heat = removal by using parallel cores could be useful in some situations – again if = you are already limited in the airflow situation, then this won’t make = much difference.  It  does suggest that using parallel cores could = result in the need for core sizes 37% smaller.  OR did I miss something = here?

 

 

 Like your data in any = case

 

Ed

 

From: Rotary motors in = aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bill = Schertz
Sent: Thursday, May 13, = 2010 10:39 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: alternative water pump

 

Back in 2002 I measured the flow from a 13-B pump, attached to the engine but driven = with an electric motor. The curve is attached. I ran the pump at 3 different = RPM, established by changing the pulley size on the motor. At 5594 rpm, the = pump produced 19 psi at zero flow, and 44 gpm at 0 psi. At lower RPM, the = pump of course pumps less.

 

The other test I did was to measure the flow through one core of the two I was = using for my installation. That is the curve going up to the right with the red = dots as the experimental points. Since I am running my cores in parallel, the = right hand rising curve is a 'calculated' flow response for the parallel = cores.

 

Finally, I hooked up the cores to the system, and pumped water through them. The = single large point represents where the flow and pressure came out, very close = to the calculated expected response.

 

All flow measurements were done by the "bucket and stop-watch" = technique, with multiple runs to get the flow.

 

Bill Schertz
KIS Cruiser #4045
N343BS
Phase I testing

 

From: Al Gietzen

Sent: Wednesday, May 12, 2010 11:54 AM

Subject: [FlyRotary] Re: alternative water pump

 

Al,

Are you sure of the 40 GPM?  = That seems like a lot.  My radiator in/out is 1.25 inches, so the water = would be traveling at 628 feet per minute at that flow rate.  That is = over 7 miles per hour!

 

Bill B

When my 20B (with a 13B pump that Atkins referred to as = ‘high flow’) was on the dyno the measured flow was 48 gpm with the = standard pulleys.  I expect the dyno cooling loop was fairly low pressure = drop compared to our typical systems, so I’m just guessing 40 gpm is in = the ballpark.  628 fpm (10.5 ft/sec) would not be considered very high = - - above 15 ft/sec I’d consider high.

Al

 

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