RV-8 Excess Cabin Pressure

[RV8RIVETER]

Would be interesting to know if those posting have aileron control boots and see if that has any effect on flow?

[Chino Tom]

In the for what its worth column, I do have airleron push tube boots.
Finally got around to venting the baggage compartment inspection cover.



Nine 5/8" holes (easier than cutting slots with a cutoff wheel). Can't tell
any difference.......

[GSchuld]

Here is an air outlet design/design theory that has been developed for the glider community. May be worth a look. Claims to both increase airflow AND have overall drag reduction potential.

Mandl air extractors:
http://www.dg-flugzeugbau.de/mandl-absaugung-e.html


Another glider pilot's report after using the mandl air extractor design on his own glider:
http://newsgroups.derkeiler.com/Arch.../msg00357.html

George

[SHIPCHIEF]

That looks good!
How does it apply to an RV-8?
No I'm not being sarcastic.
Would it go under the horizontal stab where the fiberglass fairing covers the elevator horn? which side?

[GSchuld]

http://www.aerologic.com/example/m2.html

And that's the million dollar question. The link above is a CFD workup on the one off Melmoth2. It's certainly not an RV, but you get the idea. The color spectrum runs from blue(high pressure: good for air intakes) to pink(low pressure: good in thoery for air exhaust), with green in the neutral pressure. Most would agree that it would be best to avoid exhausting cabin air out on the wings messing up the airflow. One place that really seems like a possibility is on the low pressure area up on the vertical stab(about a foot from the top and say at 40% chord.) It would require a length of ductwork from the cabin and up the verticle stab to the exhaust vent. If this were feasible, the disturbed exit air would not be running down the length of the fuse, just a brief spurt past a small section of the rudder blade then gone. I believe that some gliders have cabin air exits in this area for this reason.

I'd be curious to know if anyone has done a cfd workup on an RV?

George

[keith6261]

Anyone have any new ideas or data from this old thread?

[jliltd]

Same question here. Any updates? Is there a proven modification to keep the air off the back-seater's neck? Pressurize the aft fuselage like Cessna 180's with little forward scoops?

[PhatRV]

In Formula 1 cars, the cars have small ducts that route the high pressure air to the lower pressure region to excavate the stagnant region. If there is ducting that excavate the high pressure at the aft skirt to the lower pressure region at the floor, then that can solve it. It can probably solve another problem of not able to open the RV8 at speed if the pilot wants to eject because the high pressure pushes the canopy forward to the front windshield roll hoop.

[rv8ch]

Originally Posted by jliltd

Same question here. Any updates? Is there a proven modification to keep the air off the back-seater's neck? Pressurize the aft fuselage like Cessna 180's with little forward scoops?

Seems most have had good success with various types of "D" shaped rubber seal strips.

I have some of this rubber D strip material but I have not yet taken the time to install it.

I have a lot of air movement in the cabin coming up from the back, but I wear a lot of warm layers and pull up the hood on my hoodie if my neck gets too cold.

The real problem is if there is any moisture, like rain - it comes in and gets everywhere.

[Webb]

It’s an old thread but I have a new question. Has anyone done a smoke test to see where the air is really exiting?