X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.122] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with ESMTP id 3753968 for flyrotary@lancaironline.net; Sat, 11 Jul 2009 18:17:12 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.122; envelope-from=eanderson@carolina.rr.com Received: from computername ([75.191.186.236]) by cdptpa-omta04.mail.rr.com with ESMTP id <20090711221635398.OCAR2041@cdptpa-omta04.mail.rr.com> for ; Sat, 11 Jul 2009 22:16:35 +0000 From: "Ed Anderson" To: "'Rotary motors in aircraft'" Subject: Surface area was [FlyRotary] Re: Exit Area [FlyRotary] Re: Water Spray Pump Date: Sat, 11 Jul 2009 18:16:36 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004A_01CA0253.BACA4640" X-Mailer: Microsoft Office Outlook, Build 11.0.5510 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Thread-Index: AcoCc8v3/EwUr8vySv+RDktTNa+eOgAAP0XA In-Reply-To: Message-Id: <20090711221635398.OCAR2041@cdptpa-omta04.mail.rr.com> This is a multi-part message in MIME format. ------=_NextPart_000_004A_01CA0253.BACA4640 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Surface area of the Core, George - out of K&W streamline duct. Not an optimum necessarily, but less marginal benefit for wider opening. You might get more airflow and therefore cooling by opening it up a bit further, but you also encounter additional drag - and HP to overcome drag goes up as the cube of surface area. 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 George Lendich Sent: Saturday, July 11, 2009 6:05 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Exit Area [FlyRotary] Re: Water Spray Pump Ed, I have been looking through my notes and I can't see any notation on optimum inlet area as compared to rad area, so is that 25-30% surface area or volume of rad. My notes say exit area should be 135% or 1.35 times inlet area. Pressure build up behind the Rad is a major problem which may be resolved with exhaust augmentation, sucking the air from the cowl area. Another way may be to have a fan sucking air from the cowl or develop some low pressure suction to the cowl. One of the reasons I'm looking at the round rad is that outlet can be controlled with a simple butterfly. George (down under) Hi Bobby, 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. 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 Bobby J. Hughes Sent: Saturday, July 11, 2009 3:52 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Water Spray Pump Bill, 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. Any difference in controlling the inlet air verses traditional cowl flaps on the exit? Bobby 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 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. 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. 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: 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. My theory as to why this is difficult to fully cool includes. 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. 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 ----- From: Bobby J. Hughes To: Rotary motors in aircraft Sent: Saturday, July 11, 2009 10:44 AM Subject: [FlyRotary] Water Spray Pump 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. 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. Bobby RV-10 SC Renesis. _____ -- 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_000_004A_01CA0253.BACA4640 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Surface area of the Core, George = – out of K&W streamline = duct.  Not an optimum necessarily, but less marginal benefit for wider = opening.  You might get more airflow and therefore cooling by opening it up a bit further, = but you also encounter additional drag – and HP to overcome drag goes up = as the cube of surface area.

 

 

 

Ed

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of George Lendich
Sent: Saturday, July 11, = 2009 6:05 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Exit Area [FlyRotary] Re: Water Spray Pump

 

Ed,

I have been looking through my notes and I can't see = any notation on optimum inlet area as compared to rad area, so is that = 25-30% surface area or volume of rad. My notes say exit area should be 135% or = 1.35 times inlet area.

 

Pressure build up behind the Rad is a major problem = which may be resolved with exhaust augmentation, sucking the air from the cowl = area. Another way may be to have a fan sucking air from the cowl or develop = some low pressure suction to the cowl.

 

One of the reasons I'm looking at the round rad is = that outlet can be controlled with a simple = butterfly.

George (down under)

Hi = Bobby,

 

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.

 

Ed

 

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

 

Bill,

 

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. =

 

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

 

Bobby

 

 

 

 

 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

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.

 

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.

 

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:

 

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.

 

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

 

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.

 

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 ----- =

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

Subject: = [FlyRotary] Water Spray Pump

 

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.

 

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. =

 

Bobby

RV-10 SC Renesis.

 

--
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_000_004A_01CA0253.BACA4640--