X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-vw0-f52.google.com ([209.85.212.52] verified) by logan.com (CommuniGate Pro SMTP 5.3.7) with ESMTP id 4315318 for flyrotary@lancaironline.net; Sat, 15 May 2010 06:04:22 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.212.52; envelope-from=rwstracy@gmail.com Received: by vws5 with SMTP id 5so146836vws.25 for ; Sat, 15 May 2010 03:03:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:sender:received :in-reply-to:references:date:x-google-sender-auth:message-id:subject :from:to:content-type; bh=YCuQtiJdffM3ZP0M01pfNX5X0qVCoxzq8n3oAI7fYoU=; b=dJQ7I1WVg957OphFrTbyxQS/2fZHlc70YTtLANU9ESSNK9eqxXX2z35KMDnsqowZd2 pDWZsIpklbDaGLx62C/JZpaA97HvQtTtlVx1u5/G/3/Mc1E3BC8bjiUFpexiSqxnwEOX 2TslWYDygfB8gHcYC2KctXmC3diuVfmGrRwPE= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; b=cMDb2LCFU0gMjYS8aVNuxaGckkU9tgV4xaton4rBR5qm6nhTjhf2nN/lUPBueRUdxv xDv4nuQl79FapCYFLoU+QLtdtJkHMl2c9s0vRkqknjR9pai1O01iYNtAZ+KEh2eU8Tgw 4bqllabUryp8ncNoyaydFmwloyJ/kvYYGusn4= MIME-Version: 1.0 Received: by 10.220.63.68 with SMTP id a4mr1267896vci.9.1273917826268; Sat, 15 May 2010 03:03:46 -0700 (PDT) Sender: rwstracy@gmail.com Received: by 10.220.167.69 with HTTP; Sat, 15 May 2010 03:03:46 -0700 (PDT) In-Reply-To: References: Date: Sat, 15 May 2010 06:03:46 -0400 X-Google-Sender-Auth: VstG3rMojde_-vsbJLzEowDUb_k Message-ID: Subject: Re: [FlyRotary] Re: alternative water pump From: Tracy Crook To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=e0cb4e88790182002e04869f1b2c --e0cb4e88790182002e04869f1b2c Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable *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 thos= e 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 t= o > keep the pressure drop as low as possible. > > Interestingly, I have a thermocouple on the inlet to the cores, and one o= n > 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 coolan= t > has gone 1/2 way through the engine on the hot side. It registers somewha= t > 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 bra= in > 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 se= t > 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 coola= nt > flow. > > > > If I understood your graphs correctly, it looks like you are getting arou= nd > 20 gpm flow with a single core (so presumably you would get a bit less wi= th > two cores in series =96 but perhaps not significantly), but looks like wi= th > 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 pe= r > 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=92t change for a given power setting Y. So Q (wast= e > heat X) produced by the engine should be a constant at Y Hp. > > > > 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 =96 temp of coolant into engine) should > decrease by 37%. When you increase the mass flow and are removing the sa= me > 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* =96 not necessarily desirable, or d= oes > the Temp of coolant *out of* the engine *decrease*? Or a bit of 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 transferring more heat = per > unit time to the radiators is not going to buy you much. The reason is t= hat > 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 =96 again if you are al= ready > limited in the airflow situation, then this won=92t 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] *O= n > 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 wi= th > 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 i= s > 1.25 inches, so the water would be traveling at 628 feet per minute at th= at > flow rate. That is over 7 miles per hour! > > > > Bill B > > When my 20B (with a 13B pump that Atkins referred to as =91high flow=92) = was on > the dyno the measured flow was 48 gpm with the standard pulleys. I expec= t > the dyno cooling loop was fairly low pressure drop compared to our typica= l > systems, so I=92m 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=92d consi= der > high. > > Al > --e0cb4e88790182002e04869f1b2c Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable I also measure the temperature at the=20 engine, on the=20 block where the coolant has gone 1/2 way through the engine on the hot=20 side. It=20 registers somewhat higher, but that should be expected.
=A0
I found that same thing on the 2nd gen 13B Bill.=A0 The coola= nt temp actually drops a little on its trip past the 'cool' side of= the engine.=A0 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.=A0 My California girl friend's vacation coincid= es with those dates so I'll be spending it with her in Colorado

Tracy

On Fri, May 14, 2010 at 11:00 PM, B= ill Schertz <w= schertz@comcast.net> wrote:
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.
=A0
Interestingly, I have a thermocouple o= n the inlet=20 to the cores, and one on the exit to the cores. They show a ~5*F temperatur= e=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.
=A0
=A0
Bill Schertz
KIS Cruiser=20 #4045
N343BS
Phase I testing

Sent: Friday, May 14, 2010 5:32 PM
To: Rotary motors in aircraft <= /div>
Subject: [FlyRotary] Re: alternative water pump

Hi=20 Bill,

=A0

Had seen your = nice data=20 before, but one thing finally awoke in my old brain when I looked at it thi= s=20 time that I had not considered before.=A0 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).=A0 However, what jumped out at me this time was the real=20 significance of the parallel cores in cooling.=A0 In this case, I am assumi= ng=20 no thermostat in the coolant flow.

=A0

If I understoo= d your=20 graphs correctly, it looks like you are getting around 20 gpm flow with a s= ingle=20 core (so presumably you would get a bit less with two cores in series =96 b= ut=20 perhaps not significantly), but looks like with parallel cores you are gett= ing=20 around 32 gpm flow.=A0 That is a 20/32 =3D=A0 approx 37 %=A0 more mass=20 coolant flow through the engine.=A0=A0 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 an= d=20 size).=A0

=A0

Now the engine= is=20 producing X amount of waste heat at Y HP that it needs to get rid of.=A0 Th= at=20 won=92t change for a given power setting Y.=A0 So Q (waste heat X) produced= by=20 the=A0 engine should be a constant at Y Hp.

=A0

So taking Q = =3D=20 M*Dt/Cp and since Q (waste=20 heat)=A0 =3D constant at power setting Y, then with M (mass flow up 37%)=A0= =20 implies that in this case Dt =3D (Temp of co= olant=20 out of engine =96 temp of coolant into engine)=A0 should decrease by 37%.= =A0=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.

=A0

If that is the= case,=20 then the question is =A0- 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?=A0 I suspect it=92s a bit of both depending on the radiator=92s=20 performance.=A0 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 y= ou=20 much.=A0 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

=A0

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 airfl= ow=20 situation, then this won=92t make much difference.=A0 It =A0does suggest=20 that using parallel cores could result in the need for core sizes 37%=20 smaller.=A0 OR did I miss something here?

=A0

=A0

=A0Like your d= ata in=20 any case

=A0

Ed

=A0

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

=A0

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 changi= ng=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.

=A0

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 point= s.=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.

=A0

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

=A0

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

=A0

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

=A0

From:Al Gietzen=20

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

=A0

Al,

Are=20 you sure of the 40 GPM?=A0 That seems like a lot.=A0 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.=A0 That is over 7 miles per hour!

=A0

Bill=20 B

When my 20B (with a=20 13B pump that Atkins referred to as =91high flow=92) was on the dyno the me= asured=20 flow was 48 gpm with the standard pulleys.=A0 I expect the dyno cooling loo= p=20 was fairly low pressure drop compared to our typical systems, so I=92m just= =20 guessing 40 gpm is in the ballpark.=A0 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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