X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from qmta10.emeryville.ca.mail.comcast.net ([76.96.30.17] verified) by logan.com (CommuniGate Pro SMTP 5.3.7) with ESMTP id 4315119 for flyrotary@lancaironline.net; Fri, 14 May 2010 23:01:01 -0400 Received-SPF: pass receiver=logan.com; client-ip=76.96.30.17; envelope-from=wschertz@comcast.net Received: from omta22.emeryville.ca.mail.comcast.net ([76.96.30.89]) by qmta10.emeryville.ca.mail.comcast.net with comcast id Heb41e0021vN32cAAf0SGQ; Sat, 15 May 2010 03:00:26 +0000 Received: from WschertzPC ([71.57.77.95]) by omta22.emeryville.ca.mail.comcast.net with comcast id Hf0B1e00723NHuF8if0GzN; Sat, 15 May 2010 03:00:26 +0000 Message-ID: <7E077BF1E6BF4DF99D3781FF63F34E5B@WschertzPC> From: "Bill Schertz" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: alternative water pump Date: Fri, 14 May 2010 22:00:11 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0047_01CAF3B0.D2FEFB80" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8089.726 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8089.726 This is a multi-part message in MIME format. ------=_NextPart_000_0047_01CAF3B0.D2FEFB80 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable 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=20 Sent: Friday, May 14, 2010 5:32 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: alternative water pump Hi Bill, =20 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. =20 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). =20 =20 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. =20 So taking Q =3D M*Dt/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. =20 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.=20 =20 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? =20 =20 Like your data in any case =20 Ed =20 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 =20 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. =20 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. =20 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. =20 All flow measurements were done by the "bucket and stop-watch" = technique, with multiple runs to get the flow. =20 Bill Schertz KIS Cruiser #4045 N343BS Phase I testing =20 From: Al Gietzen=20 Sent: Wednesday, May 12, 2010 11:54 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: alternative water pump =20 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! =20 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_0047_01CAF3B0.D2FEFB80 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Ed,
I went with parallel cores to maximize = the flow=20 through the engine, and to keep the pressure drop as low as=20 possible.
 
Interestingly, I have a thermocouple on = the inlet=20 to the cores, and one on the exit to the cores. They show a ~5*F = temperature=20 drop across the cores. I also measure the temperature at the engine, on = the=20 block where the coolant has gone 1/2 way through the engine on the hot = side. It=20 registers somewhat higher, but that should be expected.
 
 
Bill Schertz
KIS Cruiser=20 #4045
N343BS
Phase I testing

Sent: Friday, May 14, 2010 5:32 PM
Subject: [FlyRotary] Re: alternative water = pump

Hi=20 Bill,

 

Had seen your = nice data=20 before, but one thing finally awoke in my old brain when I looked at it = this=20 time that I had not considered before.  We know that parallel cores = give=20 slightly better efficiency than a serial core set because the=20 DT decreases = for the=20 second core in the series compared to both parallel cores having the = same=20 DT (at least = in=20 theory).  However, what jumped out at me this time was the real=20 significance of the parallel cores in cooling.  In this case, I am = assuming=20 no thermostat in the coolant flow.

 

If I = understood your=20 graphs correctly, it looks like you are getting around 20 gpm flow with = a single=20 core (so presumably you would get a bit less with two cores in series = =96 but=20 perhaps not significantly), but looks like with parallel cores you are = getting=20 around 32 gpm flow.  That is a 20/32 =3D  approx 37 %  = more mass=20 coolant flow through the engine.   That means (all else being = equal),=20 you should transfer 37% more heat out of the engine per unit time with = the=20 parallel cores compared to the serial cores (assuming cores of same type = and=20 size). 

 

Now the = engine is=20 producing X amount of waste heat at Y HP that it needs to get rid = of.  That=20 won=92t change for a given power setting Y.  So Q (waste heat X) = produced by=20 the  engine should be a constant at Y = Hp.

 

So taking Q = =3D=20 M*Dt/Cp and = since Q (waste=20 heat)  =3D constant at power setting Y, then with M (mass flow up = 37%) =20 implies that in this case Dt =3D (Temp = of coolant=20 out of engine =96 temp of coolant into engine)  should decrease by = 37%. =20 When you increase the mass flow and are removing the same quantity of = heat, the=20 DT is of = necessity a=20 lower value.

 

If that is = the case,=20 then the question is  - does this mean the temp of coolant into the engine increases =96 not necessarily = desirable, or=20 does the Temp of coolant out = of=20 the engine decrease? Or = a bit of=20 both?  I suspect it=92s a bit of both depending on the radiator=92s = performance.  If your radiators/air flow are the limiting factors, = then=20 transferring more heat per unit time to the radiators is not going to = buy you=20 much.  The reason is that if it is not able to get rid of the heat = at the=20 faster rate and the DT between the coolant and air will be less.=20

 

But, my guess = is that=20 this theoretical increase in heat removal by using parallel cores could = be=20 useful in some situations =96 again if you are already limited in the = airflow=20 situation, then this won=92t make much difference.  It  does = suggest=20 that using parallel cores could result in the need for core sizes 37%=20 smaller.  OR did I miss something = here?

 

 

 Like = your data in=20 any case

 

Ed

 

Ed=20 Anderson

Rv-6A N494BW=20 Rotary Powered

Matthews,=20 NC

eanderson@carolina.rr.com

http://www.andersonee.com

http://www.dmack.net/mazda/index.html<= /FONT>

http://www.flyrotary.com/

http://members.cox.net/rogersda/rotary/configs.htm#N494BW

http://www.rotaryaviation.com/Rotorhead%20Truth.htm

From:=20 Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Bill Schertz
Sent: Thursday, May 13, 2010 = 10:39=20 AM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: = alternative water=20 pump

 

Back in 2002 I measured = the flow=20 from a 13-B pump, attached to the engine but driven with an electric = motor. The=20 curve is attached. I ran the pump at 3 different RPM, established by = changing=20 the pulley size on the motor. At 5594 rpm, the pump produced 19 psi at = zero=20 flow, and 44 gpm at 0 psi. At lower RPM, the pump of course pumps=20 less.

 

The other test I did was = to measure=20 the flow through one core of the two I was using for my installation. = That is=20 the curve going up to the right with the red dots as the experimental = points.=20 Since I am running my cores in parallel, the right hand rising curve is = a=20 'calculated' flow response for the parallel=20 cores.

 

Finally, I hooked up the = cores to=20 the system, and pumped water through them. The single large point = represents=20 where the flow and pressure came out, very close to the calculated = expected=20 response.

 

All flow measurements were = done by=20 the "bucket and stop-watch" technique, with multiple runs to get the=20 flow.

 

Bill Schertz
KIS = Cruiser=20 #4045
N343BS
Phase I testing

 

From: Al = Gietzen=20

Sent:=20 Wednesday, May 12, 2010 11:54 AM

To: Rotary motors in = aircraft=20

Subject:=20 [FlyRotary] Re: alternative water=20 pump

 

Al,

Are=20 you sure of the 40 GPM?  That seems like a lot.  My radiator = in/out is=20 1.25 inches, so the water would be traveling at 628 feet per minute at = that flow=20 rate.  That is over 7 miles per hour!

 

Bill=20 B

When my 20B = (with a=20 13B pump that Atkins referred to as =91high flow=92) was on the dyno the = measured=20 flow was 48 gpm with the standard pulleys.  I expect the dyno = cooling loop=20 was fairly low pressure drop compared to our typical systems, so I=92m = just=20 guessing 40 gpm is in the ballpark.  628 fpm (10.5 ft/sec) would = not be=20 considered very high - - above 15 ft/sec I=92d consider=20 high.

Al

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