X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [66.219.56.253] (HELO mail.qnsi.net) by logan.com (CommuniGate Pro SMTP 5.2.14) with ESMTP id 3754166 for flyrotary@lancaironline.net; Sat, 11 Jul 2009 21:12:31 -0400 Received-SPF: none receiver=logan.com; client-ip=66.219.56.253; envelope-from=bhughes@qnsi.net Return-Receipt-To: "Bobby J. Hughes" Subject: RE: [FlyRotary] Water Spray was] Re: Exit Area [FlyRotary] Re: Water Spray Pump Date: Sat, 11 Jul 2009 20:13:57 -0600 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01CA0296.69FCB700" Message-ID: <74120FDE88CAFE4DBDA8814BCE20A3F315E661@qnsi-mail.qnsi.net> Disposition-Notification-To: "Bobby J. Hughes" Content-class: urn:content-classes:message X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [FlyRotary] Water Spray was] Re: Exit Area [FlyRotary] Re: Water Spray Pump X-MimeOLE: Produced By Microsoft Exchange V6.5 Thread-Index: AcoCfXWlNOV2dBFWTSG/OxPTeYmXtAAFILKw References: From: "Bobby J. Hughes" To: "Rotary motors in aircraft" This is a multi-part message in MIME format. ------_=_NextPart_001_01CA0296.69FCB700 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Ed, =20 Sounds about right. Remember this is just a test to see if my oil temps will track the same 15-20F above my water. If so the question becomes, will increasing my inlet area from 21% to 26% provide the same amount of cooling as the water test. I'm not sure my oil to water exchanger can transfer more than the current 43F to the water. My flow diverter experiment restricted overall water flow to much. Only thing left is to trying lowering the coolant temp before extracting the oil heat. If this fails then a small oil to air cooler may be added.=20 =20 Just a SWAG and of course it is likely to be less than that because all the water won't turn to vapor and therefore like everything else will be something less than 100% efficient =20 A 10-15 bar spray system with small jets should produce a very nice fog. Should make for better distribution on the core face and easier vaporize. =20 Bobby =20 =20 =20 ________________________________ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Ed Anderson Sent: Saturday, July 11, 2009 4:13 PM To: Rotary motors in aircraft Subject: [FlyRotary] Water Spray was] Re: Exit Area [FlyRotary] Re: Water Spray Pump=20 Bobby, I did some rough calculations for your engine at 6400 rpm and 31 " Hg to get the BTU you needed to get rid of through the radiator (only). =20 Assuming all the water turns to vapor (which it won't, but we use lots of assumptions), and that you only need to get rid of say 10% of your additional heat (not trying to cool the entire engine output - just some delta that helps keep the cooling around 180F). I assume your basically cooling system would get rid of 90% of the heat and you just need the water for that extra 10%. =20 Assuming all of that, My calculations indicates one pint of water 100% vaporized would provide that additional cooling for approx 1.8 minutes. So if you had a gallon (8 pints) then it should provide that additional margin for around 1.8 * 8 =3D 14.4 minutes. So assuming it takes you 2 minutes to get to where your airspeed starts overcoming your cooling deficit. Then a gallon might give you sufficient water for around 6 -7 take offs before you need to refill. Just a SWAG and of course it is likely to be less than that because all the water won't turn to vapor and therefore like everything else will be something less than 100% efficient. But, a starting point. =20 Perhaps Dave Leonard can provide some real world consumption on amount of spray water to cool. =20 Ed =20 Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com =20 http://www.dmack.net/mazda/index.html =20 http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW =20 http://www.rotaryaviation.com/Rotorhead%20Truth.htm =20 ________________________________ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bobby J. Hughes Sent: Saturday, July 11, 2009 6:36 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Exit Area [FlyRotary] Re: Water Spray Pump=20 =20 Ed, =20 I agree. My inlet area is 21% or 58 sqin and my exit area is at least 200 sqin. I may open my inlets up to 26% depending on the water spray test.=20 =20 Is there any disadvantage to limiting inlet flow in cruse as opposed to exit cowl flaps? =20 Bobby =20 ________________________________ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Ed Anderson Sent: Saturday, July 11, 2009 1:32 PM To: Rotary motors in aircraft Subject: [FlyRotary] Exit Area [FlyRotary] Re: Water Spray Pump=20 Hi Bobby, =20 The theory I have read indicates that once your open area has passed 25-30% of your core area, that from that point on - exit area dominates. In other words, it does not make much difference how much more you enlarge your inlet area if the air can not get out. Air pressure simply builds under the cowl in back of the core and restricts further enhancement of thorough flow. That is if I understood what I read correctly. =20 Ed =20 Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com =20 http://www.dmack.net/mazda/index.html =20 http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW =20 http://www.rotaryaviation.com/Rotorhead%20Truth.htm =20 ________________________________ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bobby J. Hughes Sent: Saturday, July 11, 2009 3:52 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Water Spray Pump=20 =20 Bill, =20 I don't think I have a problem getting air out of the cowl. The exit area is greater than 3X the size of my inlets with no restrictions. The inlet ducts and wedge diffusers tested very good on a bench wind tunnel setup. But I need to review that data to make sure it's close to my actual flight data. I really don't have any other options for my radiator inlets other than a small enlargement. My radiators are 2.75" thick and have a denser fin count than the Griffin type Dennis and Tracy are flying. I expect Air Delta T to be better than 81F.=20 =20 Any difference in controlling the inlet air verses traditional cowl flaps on the exit? =20 Bobby =20 =20 =20 =20 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bill Schertz Sent: Saturday, July 11, 2009 12:07 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Water Spray Pump=20 Time I chimed in. I have been testing with short flights trying to get my temps in line. I cannot stay at full throttle beyond climbing to ~2500, at which point I throttle back to 5600 - 6000 rpm, and bring the speed up to 110 knots. Temps then stabilize below 200 - 205. =20 As part of my diagnostics, I have always had a air pressure differential measurement from my Blue Mountain (sigh) unit, and it would indicate ~3 to max 4 inches of water pressure difference between the front of the rad and behind it under the cowl. =20 For further information, I have installed a temporary set of pressure probes that run to a manometer in the cabin. This has told me the following: =20 1. The entrance to the rad is getting good pressure 6-7 inches water pressure, but 2. The exit is not functioning well enough, because I get 3-4 inches pressure under the cowl. =20 My theory as to why this is difficult to fully cool includes. =20 1. The cowl was designed for an air cooled engine, rejecting heat at 350 cylinder head temperature, which is a bigger driving force than we have. 2. I used the two cowl inlets in the original cowl to supply the two rads. 3. I have a third entrance for the oil cooler, so I have ~ 50% more airflow to get out of the cowl. =20 Bobby, I would install some manometers to see if it is a problem getting the air in -- or out before you modify your cowling. Bill Schertz KIS Cruiser #4045 N343BS Phase I testing ----- Original Message -----=20 From: Bobby J. Hughes =20 To: Rotary motors in aircraft =20 Sent: Saturday, July 11, 2009 10:44 AM Subject: [FlyRotary] Water Spray Pump=20 =20 Like Dennis I am having to throttle back and reduce boost after reaching pattern altitude. Flight testing this week showed I can stabilize my oil temp at 220F at 130 mph, 6400 rpm and 30" MP. Air Delta T after my radiators averaged 81F. This power setting gives a 600 fpm climb and about 185-190 HP. Not very impressive for a RV10. My initial climb out was around 1000-1250 fpm with OAT at 95F. Water temp stabilized at 200F. My oil to water exchanger was transferring 43F to the water.=20 =20 My total inlet area is 58 sqin and 21% of core face. The numbers indicate that opening my inlet area to 68 sqin or 25% should allow me to cool my full net 238 HP. Before starting major fiberglass work at 102 F I am thinking of testing a super fine mist on the radiators. I would like to see what my oil temps would be if I can drop the water temp by 10-20 degrees. The pump information attached is a 15 bar pump and meets the specification for continuous use and is safe to run dry. It's an espresso machine type pump but does not have on\off time limitations. Other pumps like his have a 1/1 or 2/1 On/Off in minutes for cooling. If lowering my water temps to 180-185F has a positive effect on oil temps then I will open my radiator duct this fall when it's cooler. Besides, I have another test for this pump. I don't have an intercooler and having a 1 pound 15 bar pump will tempt me to test manifold water injections after my super charger.=20 =20 Bobby RV-10 SC Renesis. =20 =09 ________________________________ -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html __________ Information from ESET NOD32 Antivirus, version of virus signature database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ------_=_NextPart_001_01CA0296.69FCB700 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Ed,
 
Sounds about right. Remember this is just a test = to see if my=20 oil temps will track the same 15-20F above my water. If so the question = becomes,=20 will increasing my inlet area from 21% to 26% provide the same amount of = cooling=20 as the water test.  I'm not sure my oil to water = exchanger can=20 transfer more than the current 43F to the water.  My = flow diverter=20 experiment restricted overall water flow to much. Only thing = left is to=20 trying lowering the coolant temp before extracting the oil=20 heat. If this fails then a small oil to air cooler may be added.=20
 
Just a SWAG and of course it is likely to be less = than that=20 because all the water won’t turn to vapor and therefore like = everything else=20 will be something less than 100% efficient
 
A 10-15 bar spray system with small jets should = produce a=20 very nice fog. Should make for better distribution on the core face = and=20 easier vaporize.
 
Bobby
 
 
 

From: Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net] On Behalf Of Ed=20 Anderson
Sent: Saturday, July 11, 2009 4:13 PM
To: = Rotary=20 motors in aircraft
Subject: [FlyRotary] Water Spray was] Re: = Exit Area=20 [FlyRotary] Re: Water Spray Pump

Bobby, I did = some rough=20 calculations for your engine at 6400 rpm and 31 “ Hg to get the = BTU you needed=20 to get rid of through the radiator (only).

 

Assuming all = the water=20 turns to vapor (which it won’t, but we use lots of assumptions), = and that you=20 only need to get rid of say 10% of your additional heat (not trying to = cool the=20 entire engine output – just some delta that helps keep the cooling = around=20 180F).  I assume your basically cooling system would get rid of 90% = of the=20 heat and you just need the water for that extra=20 10%.

 

Assuming all = of that,=20 My calculations indicates one pint of water 100% vaporized would provide = that=20 additional cooling for approx 1.8  minutes.  So if you had a = gallon (8=20 pints) then it should provide that additional margin for around 1.8 * 8 = =3D 14.4=20 minutes.  So assuming it takes you 2 minutes to get to where your = airspeed=20 starts overcoming your cooling deficit. Then a gallon might give you = sufficient=20 water for around 6 -7 take offs before you need to refill.  Just a = SWAG and=20 of course it is likely to be less than that because all the water = won’t turn to=20 vapor and therefore like everything else will be something less than = 100%=20 efficient.  But, a starting point.

 

Perhaps Dave = Leonard=20 can provide some real world consumption on amount of spray water to=20 cool.

 

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

http://www.flyrotary.com/

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

http://www.r= otaryaviation.com/Rotorhead%20Truth.htm

From:=20 Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Bobby J. Hughes
Sent: Saturday, July 11, 2009 = 6:36=20 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: Exit = Area=20 [FlyRotary] Re: Water Spray Pump

 

Ed,

 

I agree. My = inlet area=20 is 21% or 58 sqin and my exit area is at least 200 sqin. I may = open my=20 inlets up to 26% depending on the water spray test.=20

 

Is there any=20 disadvantage to limiting inlet flow in cruse as opposed to exit cowl=20 flaps?

 

Bobby

 

From:=20 Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Ed Anderson
Sent: Saturday, July 11, 2009 = 1:32=20 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Exit Area = [FlyRotary]=20 Re: Water Spray Pump

Hi=20 Bobby,

 

The theory I = have read=20 indicates that once your open area has passed 25-30% of your core area, = that=20 from that point on - exit area dominates. In other words, it does not = make much=20 difference how much more you enlarge your inlet area if the air can not = get=20 out.  Air pressure simply builds under the cowl in back of the core = and=20 restricts further enhancement of thorough flow.  That is if I = understood=20 what I read correctly.

 

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

http://www.flyrotary.com/

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

http://www.r= otaryaviation.com/Rotorhead%20Truth.htm

From:=20 Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Bobby J. Hughes
Sent: Saturday, July 11, 2009 = 3:52=20 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: Water = Spray Pump=20

 

Bill,

 

I don't think = I=20 have a problem getting air out of the cowl.  The exit = area is=20 greater than 3X the size of my inlets with no restrictions. The inlet = ducts and=20 wedge diffusers tested very good on a bench wind tunnel setup. But I = need to=20 review that data  to make sure it's close to my actual=20 flight data. I really don't have any other options for my = radiator inlets other than a small enlargement.  My = radiators are=20  2.75" thick and have a denser fin count than the Griffin = type Dennis=20 and Tracy are flying. I expect Air Delta T to be better than 81F.=20

 

Any difference in=20 controlling the inlet air verses traditional cowl flaps on the=20 exit?

 

Bobby

 

 

 

 

 From:=20 Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Bill Schertz
Sent: Saturday, July 11, 2009 = 12:07=20 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: Water = Spray Pump=20

Time I chimed in. I have = been=20 testing with short flights trying to get my temps in line. I cannot stay = at full=20 throttle beyond climbing to ~2500, at which point I throttle back to = 5600 - 6000=20 rpm, and bring the speed up to 110 knots. Temps then stabilize below 200 = -=20 205.

 

As part of my diagnostics, = I have=20 always had a air pressure differential measurement from my Blue Mountain = (sigh)=20 unit, and it would indicate ~3 to max 4 inches of water pressure = difference=20 between the front of the rad and behind it under the=20 cowl.

 

For further information, I = have=20 installed a temporary set of pressure probes that run to a manometer in = the=20 cabin. This has told me the = following:

 

1. The entrance to the rad = is=20 getting good pressure 6-7 inches water pressure,=20 but

2. The exit is not = functioning well=20 enough, because I get 3-4 inches pressure under the=20 cowl.

 

My theory as to why this = is=20 difficult to fully cool includes.

 

1. The cowl was designed = for an air=20 cooled engine, rejecting heat at 350 cylinder head temperature, which is = a=20 bigger driving force than we have.

2. I used the two cowl = inlets in the=20 original cowl to supply the two rads.

3. I have a third entrance = for the=20 oil cooler, so I have ~ 50% more airflow to get out of the=20 cowl.

 

Bobby, I would install = some=20 manometers to see if it is a problem getting the air in -- or out before = you=20 modify your cowling.

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

----- Original Message = -----=20

From: Bobby J. = Hughes=20

To: Rotary motors in = aircraft=20

Sent: Saturday,=20 July 11, 2009 10:44 AM

Subject:=20 [FlyRotary] Water Spray Pump

 

Like Dennis I am having = to=20 throttle back and reduce boost after reaching pattern altitude. Flight = testing=20 this week showed I can stabilize my oil temp at 220F at 130 mph, 6400=20 rpm and 30" MP. Air Delta T after my radiators averaged = 81F. This=20 power setting gives a 600 fpm climb and about 185-190 HP. Not very = impressive=20 for a RV10. My initial climb out was around 1000-1250 fpm with = OAT at=20 95F. Water temp stabilized at 200F.  My oil to water = exchanger=20 was transferring 43F to the water. =

 

My total inlet area is = 58 sqin and=20 21% of core face. The numbers indicate that opening my inlet area to = 68 sqin=20 or 25% should allow me to cool my full net 238 HP.  Before = starting=20 major fiberglass work at 102 F I am thinking of testing a super fine = mist on=20 the radiators. I would like to see what my oil temps would be if = I can=20 drop the water temp by 10-20 degrees. The pump information = attached is a=20 15 bar pump and meets the specification for continuous use and is safe = to run=20 dry. It's an espresso machine type pump but does not have on\off = time=20 limitations. Other pumps like his have a 1/1 or 2/1 On/Off in minutes = for=20 cooling.  If lowering my water temps to 180-185F has a positive = effect on=20 oil temps then I will open my radiator duct this fall when it's = cooler.=20 Besides, I have another test for this pump. I don't have an = intercooler and=20 having a 1 pound 15 bar pump will tempt me to test manifold water = injections=20 after my super charger.

 

Bobby

RV-10 SC=20 Renesis.

 

--
Homepage: =20 http://www.flyrotary.com/
Archive and UnSub:  =20 = http://mail.lancaironline.net:81/lists/flyrotary/List.html



__________ Information from ESET NOD32 = Antivirus, version of virus signature database 3267 (20080714)=20 __________

The message was checked by ESET NOD32 = Antivirus.

http://www.eset.com



__________ Information from ESET NOD32 = Antivirus, version of virus signature database 3267 (20080714)=20 __________

The message was checked by ESET NOD32 = Antivirus.

http://www.eset.com

------_=_NextPart_001_01CA0296.69FCB700--