X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.121] verified) by logan.com (CommuniGate Pro SMTP 5.3.11) with ESMTP id 4647275 for flyrotary@lancaironline.net; Sun, 19 Dec 2010 17:17:16 -0500 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.121; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.1 cv=3jtQBdTzPyV+fq4oCU/u8ZPrJJGN11HvhaDVxyWhycI= c=1 sm=0 a=cVHxHVjsHKoA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:17 a=Ia-xEzejAAAA:8 a=arxwEM4EAAAA:8 a=r1ClD_H3AAAA:8 a=kviXuzpPAAAA:8 a=3oc9M9_CAAAA:8 a=HZJGGiqLAAAA:8 a=8hdTUVCddbLJMkjub-0A:9 a=lWBHQ7fOq6tmKybPRoEA:7 a=3ILbUXnOigoXgxOw0Md1LYzHrWEA:4 a=wPNLvfGTeEIA:10 a=EzXvWhQp4_cA:10 a=4vB-4DCPJfMA:10 a=U8Ie8EnqySEA:10 a=HeoGohOdMD0A:10 a=EO_nVC7gmfCmE5kn:21 a=9iejliNnbugQd9x4:21 a=pedpZTtsAAAA:8 a=UretUmmEAAAA:8 a=s_1WBLeSzZ95vkquhboA:9 a=-0hHuGO0BeCEQXdAgjUA:7 a=NiQvtQHkM7GhPArbvRvtNWcDFJwA:4 a=eJojReuL3h0A:10 a=iVkDmfvjeKcA:10 a=QMgLP98K4zeeCAiV:21 a=miL7vNrS5_KWnb4W:21 a=rPkcCx1H5rrOSfN0dPC7kw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.167.5 Received: from [174.110.167.5] ([174.110.167.5:56633] helo=EdPC) by cdptpa-oedge02.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id 43/DE-02631-8448E0D4; Sun, 19 Dec 2010 22:16:41 +0000 Message-ID: From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: Fw: Water temps Date: Sun, 19 Dec 2010 17:16:39 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_01DE_01CB9FA0.7FEA8210" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 This is a multi-part message in MIME format. ------=_NextPart_000_01DE_01CB9FA0.7FEA8210 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Bill, No I keep mine at a small private airport called GooseCreek (28A), but = Monore is only about 4 miles from home. Ed From: Bill Bradburry=20 Sent: Sunday, December 19, 2010 4:54 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: Fw: Water temps Ed, Do you keep your plane at the Munroe Airport? =20 Bill B =20 -------------------------------------------------------------------------= ------- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On = Behalf Of Ed Anderson Sent: Sunday, December 19, 2010 4:10 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Fw: Water temps =20 Looking at it from Q =3D MDt*cp. We know that the coolant mass flow ( = M ) through the system (both coolant and air) is going to be a constant = at some specific power setting and air speed. With an oil/coolant heat = exchange as part of the system - then the waste heat (Q) must be = exchanged with the air through the radiator. Therefore the efficiency = of the radiator in discharging heat to the air is an important = consideration. The more efficient - the smaller the radiator required = and lower cooling drag possible. =20 So since we want to get rid of the same total Heat Q and since mass flow = and Specific heat is constant that only leaves Dt as a factor to play = with. So all else being the same, the configuration that produces the = greatest Dt between coolant and air will be the most efficient and = require the smaller radiator. =20 So if the coil cooler exchange is placed on the Hot side of the = radiator, that would increase the temperature of the coolant going into = the radiator and provided a larger Dt (more efficient) than if it were = placed on the Cool side of the radiator. If placed on the cool side = there is a greater transfer of oil heat to the coolant , since the = coolant has already passed through the radiator and is lower temp, but = that results in a higher temperature coolant going back into the engine. = To keep the coolant temperature at the same level prior to inserting = the oil/coolant exchanger into the circuit requires (as Tracy pointed = out) you to lower the coolant temp even more before it goes into the = oil/coolant exchanger by using a larger radiator. =20 Since the objective is to remove heat most efficiently from the engine = (and hopefully keep cooling drag down), it would appear that the = oil/coolant heat exchanger being placed on the hot side of the radiator = offers an overall advantage from that perspective. Clearly either way, = it can be made to work. =20 Ed =20 Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 http://www.andersonee.com http://www.eicommander.com =20 From: Tracy=20 Sent: Sunday, December 19, 2010 3:39 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: Fw: Water temps =20 "no matter which leg of the coolant system you pick up the heat from the = oil cooler, you raise the temp of the coolant loop by the amount of = additional heat; so the rejection temp of the rad is higher either way." Not so fast! Here's my take on it. =20 Yes, the total heat rejection of the rad has to end up being the same. = BUT with the cold side oil cooler, to keep the engine coolant inlet = temperature (and temperature of the engine block) the same requires a = 33% larger rad (compared to what we needed a separate air to oil = cooler). Actually, the rad has to be even bigger than this because we = have to have the rad outlet temp even lower to compensate for the rise = in coolant temp due to temp rise of oil cooler. That means the median = temp of the rad is lower and therefore less efficient. If you cool the oil on the hot side of the coolant circuit, the inlet = temp of the rad is now higher than in the cold side scheme and the = required rad size and/or the airflow through the rad size increase is = smaller due to the higher delta T between air and rad. This results in = less cooling drag.=20 That's my story & I'm stick'n to it : ) Tracy On Sun, Dec 19, 2010 at 12:13 PM, Al Gietzen wrote: For maximum cooling of the oil from an oil/water HX (heat exchanger) = you'll want to plumb the oil from engine out to the cooler; and plumb = the cooler between the radiator and the engine return. And I'm not = quite sure about Tracy's point because no matter which leg of the = coolant system you pick up the heat from the oil cooler, you raise the = temp of the coolant loop by the amount of additional heat; so the = rejection temp of the rad is higher either way. The assumption is, of = course, that you have sufficient capacity to keep the coolant exiting = the engine below boiling for extended high power. =20 On my Velocity 20B installation I have a primary radiator in the cowl, = and a secondary in the wing root; plumbed in parallel. The wing root rad = has an in-line 170F thermostat, and generally only comes on line during = extended climb. No thermostat in the engine that would restrict flow and = add a potential failure mode. =20 I have an oil/air cooler and an oil/coolant HX, also plumbed in = parallel. The oil/coolant HX is plumbed to the exit of the primary rad. = The oil temp runs about 20F higher than the coolant (measured at oil = return and coolant out). I could probably reduce that difference by = restricting flow to the oil/air cooler forcing more through the = oil/coolant HX; but I'm quite happy with the way things work. =20 =20 Over 200 hours and lovin' my rotary more all the time. =20 Al G =20 ----- Forwarded Message ---- From: "CozyGirrrl@aol.com" To: keltro@att.net Sent: Mon, December 13, 2010 4:05:31 PM Subject: Re: Fw: [FlyRotary] Re: Fw: Water temps Thanks Tracy for the adjustment in my thinking. I don't want to target = temps unrealistically.=20 Where does that leave us with our pick up and return points for the = oil/water cooling system? If the oil were being cooled with water only = and we wanted the best possible chance at that, wouldn't we want to feed = it the cooler water from the high pressure side of the pump prior to = entering the block? =20 Whatever space we would use for an oil/air cooler takes away from = potential coolant radiator space. Putting the two side by side becomes = less efficient spacewise for both due to losses for structure etc. If it = is not possible to cool the oil adequately with water alone then we'll = need to back up a little and make other layout plans. I remember = Richter's Cozy III with three P-51 scoops, it got the job done but was = like dragging a parachute in drag. =20 Kelly, to your comment below, while I am sure we'd have no problem = putting adequate heat into the oil, I am very concerned about keeping = any more than just enough out of it. Much easier going one way then the = other =3D) ...Chrissi =20 In a message dated 12/13/2010 2:49:02 P.M. Central Standard Time, = keltro@att.net writes: Chrissi, My own opinion is that after warm up and in flight the oil temp = leaving the engine before the=20 coolers (air or water to oil) will almost always be well above = 160-180 F..............If it is not this high then the oil to water cooler will actually help warm it to a more = efficient temp.........IMHO =20 Somebody correct me if this is a fallacy = !!.......................<:) =20 Kelly Troyer "DYKE DELTA JD2" (Eventually) "13B ROTARY"_ Engine "RWS"_RD1C/EC2/EM2 "MISTRAL"_Backplate/Oil Manifold "TURBONETICS"_TO4E50 Turbo =20 =20 -------------------------------------------------------------------------= ----- From: "CozyGirrrl@aol.com" To: keltro@att.net Sent: Mon, December 13, 2010 12:52:06 PM Subject: Re: Fw: [FlyRotary] Re: Fw: Water temps This is where I get confused: =20 said previously,=20 -ideal water temp =3D 160*~180*F -ideal oil temp =3D 160*F =20 If we are cooling oil with water that is at best hotter than the ideal = temp of the oil, then are we not adding heat to it rather than removing = it?=20 =20 If we are trying to cool oil, why would we feed the highest temp water = to the oil/water cooler rather than the coolest temp water by tapping = into the pump housing where it enters the block? =20 Based on feedback, the water entering the block may be as low as = 150*~160*F, would this be cool enough to do an adequate job of cooling = the oil? =20 Also, which model of Mocal is being used? =20 ...Chrissi =20 ------=_NextPart_000_01DE_01CB9FA0.7FEA8210 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Bill,
 
No I keep mine at a small private airport called = GooseCreek (28A), but Monore is only about 4 miles from = home.
 
Ed

Sent: Sunday, December 19, 2010 4:54 PM
Subject: [FlyRotary] Re: Fw: Water temps

Ed,

Do you keep = your plane=20 at the Munroe=20 Airport?=

 

Bill=20 B

 

From:=20 Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Ed Anderson
Sent: Sunday, December 19, 2010 = 4:10=20 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: Fw: = Water=20 temps

 

Looking at it from Q =3D=20 MDt*cp.  We know that = the  coolant mass=20 flow ( M ) through the system (both coolant and air) is going = to be a=20 constant at some specific power setting and air speed.  With an = oil/coolant=20 heat exchange as part of the system - then the waste heat (Q) must be = exchanged=20 with the air through the radiator.  Therefore the efficiency of the = radiator in discharging heat to the air is an important = consideration.  The=20 more efficient - the smaller the radiator required and lower cooling = drag=20 possible.

 

So since we want to get = rid of the=20 same total Heat Q and since mass flow and Specific heat is constant that = only=20 leaves Dt as a factor to play with.  So all = else being=20 the same, the configuration that produces the greatest = Dt between coolant and = air will be=20 the most efficient and require the smaller=20 radiator.

 

So if the coil cooler = exchange is=20 placed on the Hot side of the radiator, that would increase the = temperature of=20 the coolant going into the radiator and provided a larger = Dt (more efficient) =  than if it=20 were placed on the Cool side of the radiator.    If = placed on the=20 cool side there is a greater transfer of oil heat to the coolant , = since=20 the coolant has already passed through the radiator and is lower temp, = but that=20 results in a higher temperature coolant going back into the = engine. =20 To keep the coolant temperature at the same level prior to = inserting the=20 oil/coolant exchanger into the circuit requires (as Tracy pointed = out)=20 you  to lower the coolant temp even more before it goes into the=20 oil/coolant exchanger by using a  larger=20 radiator.

 

Since the objective is to = remove=20 heat most efficiently from the engine (and hopefully keep cooling drag = down), it=20 would appear that the oil/coolant heat exchanger being placed on the hot = side of=20 the radiator offers an overall advantage from that perspective.  = Clearly=20 either way, it can be made to work.

 

Ed

 

Edward L. = Anderson
Anderson = Electronic=20 Enterprises LLC
305 = Reefton=20 Road
Weddington, NC = 28104
http://www.andersonee.c= om
http://www.eicommander.com

 

From: Tracy=20

Sent: Sunday,=20 December 19, 2010 3:39 PM

To: Rotary motors in = aircraft=20

Subject:=20 [FlyRotary] Re: Fw: Water = temps

 

"no=20 matter which leg of the coolant system you pick up the heat from the oil = cooler,=20 you raise the temp of the coolant loop by the amount of additional heat; = so the=20 rejection temp of the rad is higher either way."


Not so=20 fast!   Here's my take on it.  

Yes,  =20 the total heat = rejection of the=20 rad has to end up being the same.  BUT with the cold side oil = cooler, to=20 keep the engine coolant inlet temperature (and temperature of the engine = block)=20 the same requires a 33% larger rad (compared to what we needed a = separate air to=20 oil cooler).   Actually, the rad has to be even bigger than = this=20 because we have to have the rad outlet temp even lower to compensate for = the=20 rise in coolant temp due to temp rise of oil cooler.   That = means the=20 median temp of the rad is lower and therefore less efficient.

If = you cool=20 the oil on the hot side of the coolant circuit,  the inlet temp of = the rad=20 is now higher than in the cold side scheme and the required rad size = and/or the=20 airflow through the rad size increase is smaller due to the higher delta = T=20 between air and rad.  This results in less cooling drag. =

That's my=20 story & I'm stick'n to it : )

Tracy

On Sun, Dec 19, 2010 at 12:13 PM, = Al Gietzen <ALVentures@cox.net>=20 wrote:

For maximum = cooling=20 of the oil from an oil/water HX (heat exchanger) you=92ll want to plumb = the oil=20 from engine out to the cooler; and plumb the cooler between the radiator = and the=20 engine return.  And I=92m not quite sure about Tracy=92s point because no matter = which leg of=20 the coolant system you pick up the heat from the oil cooler, you raise = the temp=20 of the coolant loop by the amount of additional heat; so the rejection = temp of=20 the rad is higher either way.  The assumption is, of course, that = you have=20 sufficient capacity to keep the coolant exiting the engine below boiling = for=20 extended high power.

 

On my = Velocity 20B=20 installation I have a primary radiator in the cowl, and a secondary in = the wing=20 root; plumbed in parallel. The wing root rad has an in-line 170F = thermostat, and=20 generally only comes on line during extended climb. No thermostat in the = engine=20 that would restrict flow and add a potential failure=20 mode.

 

I have an = oil/air=20 cooler and an oil/coolant HX, also plumbed in parallel. The oil/coolant = HX is=20 plumbed to the exit of the primary rad.  The oil temp runs about = 20F higher=20 than the coolant (measured at oil return and coolant out). I could = probably=20 reduce that difference by restricting flow to the oil/air cooler forcing = more=20 through the oil/coolant HX; but I=92m quite happy with the way things = work. =20

 

Over 200 = hours and=20 lovin=92 my rotary more all the time.

 

Al=20 G

 

----- Forwarded Message=20 ----
From: "CozyGirrrl@aol.com" <CozyGirrrl@aol.com>
To: keltro@att.net
Sent: Mon, December 13, 2010 = 4:05:31=20 PM
Subject: Re: Fw: = [FlyRotary]=20 Re: Fw: Water temps

Thanks = Tracy for the = adjustment=20 in my thinking. I don't want to target temps unrealistically.=20

Where does = that leave=20 us with our pick up and return points for the oil/water cooling system? = If the=20 oil were being cooled with water only and we wanted the best possible = chance at=20 that, wouldn't we want to feed it the cooler water from the high = pressure side=20 of the pump prior to entering the = block?

 

Whatever = space we=20 would use for an oil/air cooler takes away from potential coolant = radiator=20 space. Putting the two side by side becomes less efficient spacewise for = both=20 due to losses for structure etc. If it is not possible to cool the oil=20 adequately with water alone then we'll need to back up a little and make = other=20 layout plans. I remember Richter's Cozy III with three P-51 scoops, it = got the=20 job done but was like dragging a parachute in=20 drag.

 

Kelly, to = your comment=20 below, while I am sure we'd have no problem putting adequate heat into = the oil,=20 I am very concerned about keeping any more than just enough out of it. = Much=20 easier going one way then the other = =3D)

...Chrissi

 

In a message = dated=20 12/13/2010 2:49:02 P.M. Central Standard Time, keltro@att.net = writes:

Chrissi,

   =20 My own opinion is that after warm up and in flight the oil temp = leaving the=20 engine before the

coolers = (air or=20 water  to oil) will almost always be well above=20 160-180 F..............If it is not=20 this

high then=20 the oil to water cooler will actually help warm it to a more = efficient=20 temp.........IMHO

 

  =20 Somebody correct me if this is a fallacy=20 !!.......................<:)

 

Kelly=20 Troyer
"DYKE=20 DELTA JD2"=20 (Eventually)

"13B = ROTARY"_=20 Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil=20 Manifold

"TURBONETICS"_TO4E50=20 Turbo

 

 

From: "CozyGirrrl@aol.com" <CozyGirrrl@aol.com>
To: keltro@att.net
Sent: Mon, December 13, 2010 = 12:52:06=20 PM
Subject: Re: Fw: = [FlyRotary] Re: Fw: Water temps

This is = where I get=20 confused:

 

said = previously,=20

-ideal = water temp =3D=20 160*~180*F

-ideal oil = temp =3D=20 160*F

 

If we are = cooling=20 oil with water that is at best hotter than the ideal temp of the oil, = then are=20 we not adding heat to it rather than removing it?=20

 

If we are = trying to=20 cool oil, why would we feed the highest temp water to the oil/water = cooler=20 rather than the coolest temp water by tapping into the pump housing = where it=20 enters the block?

 

Based on = feedback,=20 the water entering the block may be as low as 150*~160*F, would this = be cool=20 enough to do an adequate job of cooling the=20 oil?

 

Also, = which model of=20 Mocal is being used?

 

...Chrissi

 

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