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aerospace student needs rudder specifications

N

Nico_Aero11

I'm New Here
Hey everyone, first time post for me.
I am looking for some specifications about the RV-7 rudder. I am trying to map out the RV-7 in Simulink to do some lateral and longitudinal controls analysis just like my class taught me, the only problem is I have all these equations and no numbers specific to the RV-7. If anyone has a booklet, plans, schematics, links, or a new direction that I could search I would be most appreciative of your help.

Things I'm looking for:

Area_rudder
CL_rudder
efficiency factor of vertical tail
Tail airfoil type
Vertical Tail volume

if you have access or may know where to find these things that would be great!


Nick R.
Aerospace Engineering Undergraduate
California Polytechnics State University
 
Call Vans

Nick,

You may want to contact Van's. It's likely they're the only ones who will have easy access to the info you seek. Alternately, I suspect there are several builders / owners of RV-7s who would allow you to take measurements of their -7 tail. There is a very active RV group in Southern California.

Good luck.
 
I tried calling them, but from what I have gathered Van's Aircraft is primarily a sheet aluminum manufacturer, and at least the people running the phone lines don't have access or don't want to bother the engineers for that information. I guess some hand measurements wouldn't be impossible to get, we have an RV-7 that was built for Cal Poly testing purposes.

I was just hoping that someone had a booklet that had all these little numbers and specifications to the RV-7. Going try to track down some central coast RV-7 pilots too. Thanks for the response
 
Nick, I'm also an Engineer and building a -7...I have not seen any Engineering data for the RV7 like you are requesting. The plans do not include this type of information unfortunately. Your best bet is try to get a hold of someone at Van's with technical knowledge (which it sounds like you did)...outside of that, probably have to do measurements and your own calculations as much as possible. I would be interested in seeing your work when you are done however. I do have this link in my archives that might help, also from Cal Poly, you probably are already aware of this I would guess?

http://aerosim.calpoly.edu/files/Masters Thesis - Robert Little.pdf

Best of luck,
 
Nick,

I don't have any access to the data you're looking for but maybe you can figure out some answers to your questions.

Area_rudder
Get a 3-View of the 7 from Van's site and then "calibrate" the scale based on the published length/wingspan figures. From there you should be able to estimate pretty well.

Tail airfoil type
Something simple and symmetric. I bet a NACA 0012 is close.

CL_rudder
Guess something reasonable based on rudder deflection and CL vs. flap deflection curves for the airfoil (use charts or Xfoil).

Vertical Tail volume
I think this is something that can be computed from the wing to empennage distance and the area of the stab.

efficiency factor of vertical tail
Don't know, guess something reasonable.

I can promise that all of the values above will be wrong, but the neat thing is that the answer will still probably be pretty close.

Think of this:
The SR-71, a Mach 3.3 80,000ft ramjet aircraft, first flew in 1964 and still holds numerous speed records. It was designed without simulink or even programmable calculators.

Pretty cool in this engineer's opinion.
-DC
 
I got a different response some time ago ...

Nico_Aero11 said:
I tried calling them, but from what I have gathered Van's Aircraft is primarily a sheet aluminum manufacturer, and at least the people running the phone lines don't have access or don't want to bother the engineers for that information. I guess some hand measurements wouldn't be impossible to get, we have an RV-7 that was built for Cal Poly testing purposes.

I was just hoping that someone had a booklet that had all these little numbers and specifications to the RV-7. Going try to track down some central coast RV-7 pilots too. Thanks for the response
Click to expand...

While mentoring a high school student for science project, I called Van's and spoke to an engineer there. Had a nice chat about the *wing* (a variation on NACA 23013 as I recall).

Try calling again and ask for tech support. Tell then about your project and they will probably get you to the right person.

If you have already done that, I would still suggest trying again. They have never refused to answer any questions I have put forth over the years.

James
 
Thanks for all the help guys, I am currently tracking down the Grumman American AA-1 aircraft which is very similar to the RV-7, maybe someone has some information about this plane or has heard of it?.

Basically I am trying to find some published results about these aircraft performances to make my controls analysis as close to the real thing as possible, but I guess that is what comes with an experimental aircraft, it is constantly an experiment!

I will keep everyone posted with whatever I find.


I like your thinking Digidoc, that plane was a testament to what can be built with a "gung-ho" engineering attitude, along with sending men to the moon in a spacecraft less complex than a 2010 BMW, or have a man jump from the edge of space in the 40's.

Thanks everyone!

-Nick R.
Aerospace Engineering Undergraduate
California Polytechnic State University
 
Nick, I'd go with what Digidocs and RV7Ron suggested. Reverse-engineering is not just a practice, it is a skill and a very important one.

For the various dimensions, a tape measure will get you every bit as close as you need.

For the profiles, I suggest you just steal the airfoils.

Thanks, Bob K.
 
I'm in SLO

Nick,
I own an RV-7, I'm in SLO, and I started the class that resulted in Poly building their RV-7. If you want to come look at mine, you're welcome to. Drop me a PM.
Paul
 
Nick,
The engineers at Van's probably know the data you are looking for, but I think the easiest way is to reverse engineer it by downloading the "3 View All RVs" from their website:
http://www.vansaircraft.com/public/downloads.htm
These are to 1:1 scale in Autocad, so you can easily calculate the areas, hingelines and moment arms you are looking for. In addition to the rudder you can do the same for the elevators, ailerons and flaps.
Wing airfoil on the RV-7 is a NACA 23013.5 I believe, don't know if it is the MOD version or not. Horizontal and vertical stab are probably NACA 0012, if not, this will be close enough. Wing on the RV-9 is a custom airfoil and horizontal stab is a NACA 6XXXXX series so you're probably better off analyzing the RV-7.
 
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