Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

NACA VENTS

Matronics Email Lists Forum Index -> Rocket-List

View previous topic :: View next topic

Author Message

fconsult(at)telus.net
Guest

Posted: Tue Feb 28, 2006 2:31 pm Post subject: NACA VENTS

James

       For what its worth ,my RV4 has a Naca vent just above the rear canopy

rail in the back seat and the air flows out of the vent instead of blowing

in. It is allowing warm air to escape fom inside instead of cooling air

flowing in.



                              Chris

- The Matronics Rocket-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Rocket-List

James Baldwin

Joined: 16 Jan 2006
Posts: 23

Posted: Tue Feb 28, 2006 3:51 pm Post subject: NACA VENTS

Chris -

I'm sure this is not the first time this subject has been discussed and 

there are many different results with similar vent locations.  Yours is 

yet another result that must have some explanation.  Is your fuselage 

vented elsewhere exhausting the cockpit air?  Obviously the pressure 

inside the cockpit is greater than the local pressure outside the vent, 

so I'd be interested to know what your strategy was during building.  Of 

course, maybe you like it the way it is?  JBB.



Chris Fordham wrote:



 	  Quote: 	
		  



James

       For what its worth ,my RV4 has a Naca vent just above the rear canopy

rail in the back seat and the air flows out of the vent instead of blowing

in. It is allowing warm air to escape fom inside instead of cooling air

flowing in.



                              Chris

- The Matronics Rocket-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Rocket-List

Lee Logan

Joined: 10 Jan 2006
Posts: 86

Posted: Tue Feb 28, 2006 4:15 pm Post subject: NACA VENTS

Another good vent location that will do the same thing is to louver one of

both of your aft inspection plates (just under the stabilizer on my RV-4).

Will make your vents more effective in that it will draw air through the

fuselage with a venturi effect.



On 2/28/06, Chris Fordham <fconsult(at)telus.net> wrote:

 	  Quote: 	
		  

 



 James

       For what its worth ,my RV4 has a Naca vent just above the rear

 canopy

 rail in the back seat and the air flows out of the vent instead of blowing

 in. It is allowing warm air to escape fom inside instead of cooling air

 flowing in.



                              Chris

- The Matronics Rocket-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Rocket-List

fconsult(at)telus.net
Guest

Posted: Wed Mar 01, 2006 8:28 am Post subject: NACA vents

Hi James

             I bought the RV4 5years ago now so I didn't plan the position 

of the NACA vents. There is two on the right hand canopy skirt one for the 

pilot and one for the pax, and both exhaust air instead of blowing air. My 

thoughts is this is a low pressure area on the side of the a/c and the air 

is being sucked out. There is also vents on either side of the front 

fuselage below the split line and these provide alot of cold air. Most of 

the time it is comfortable flying here in the winter with all the vents 

closed and the heater on full. In summer or if I go down California way the 

rear seater sometimes doesn't get enough cool air.

  On the HR 2  I've put an intake under the wing for the passenger and 

haven't quite decided what to do for the front seat.

                                      Chris

                                do not archive

- The Matronics Rocket-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Rocket-List

Vince Frazier

Joined: 10 Jan 2006
Posts: 132

Posted: Wed Mar 01, 2006 10:28 am Post subject: NACA vents

SNIP  Vince F..... I would be curious if your OAT (pickup in front)

ever acts in non-linear fashion... suspecting maybe heat soak ... or

reflecting backflow at



certain airspeeds. If you slow down, does the temp OAT cool  down ?

John Meyers   SNIP

************************************************************************

*********



Non-linear??  backflow?  Heat soak?  Wow, no offense, but we're talking

about a simple case of hot air coming in here.    This thread

prompted me to go take some actual measurements yesterday using the OAT

and a regular, non-electrical, alcohol thermometer.  TWO thermometers,

not one.  And the alcohol thermometer confirmed that the OAT thermometer

was dead on.



 	  Quote: 	
		  From numbers that I took from the OAT gauge a few days ago, I was

getting as much as a 15 or 20 degree difference in the front and rear
	


vents.  



My cowl louvers were closed during that earlier flight.  I had opened

the louvers up for the flight mentioned below. Unfortunately I didn't

have a rear vent thermometer reading for the flights when the louvers

were closed, but having the louvers opened did seem to make the front

vent temps cooler. 



Results showed that the front vents (both of them) were putting out 66

degree F air and the rear vent was putting out 57 degree F air.  Hmmm, 9

degrees difference.  Not the 15 or 20 that I saw on a 30 degree day with

the louvers closed, but still considerably different.   FWIW, the air

temp on the ground was about 64 degrees F, so the rear vent was putting

out air at the temp that I'd expect at 3500' and the front vent was

heating it up somewhat. 



In addition to having the louvers opened this time, I also taped over

the cowl seams on the left side of the plane.  This had no effect on the

temps, both left and right front vents were the same.



I'll take a thermometer with me for the next several times that I fly

and see if this pattern is consistent.



I can't say why Greg Nelson's gets cool air and I don't.  Probably

because of a difference in   engine cooling set up.   Maybe it's a

climate difference between Indiana (wx always humid) and wherever Greg

lives (California?)?



I stand by my earlier comment, if I were installing NACA vents again,

I'd put them under the wing or someplace other than on the fuselage

sides.  YMMV.



Vince

- The Matronics Rocket-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Rocket-List

_________________
Vince Frazier
3965 Caborn Road
Mount Vernon, IN 47620
812-464-1839 work
812-985-7309 home
F-1H Rocket, N540VF
http://vincesrocket.com/

Display posts from previous:

	Matronics Email Lists Forum Index -> Rocket-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum