Student needs information

[th8270s]

Hello folks,

I am an aerospace student from Germany. In the moment I am working on my bachelor thesis, which describes the flight testing program, referred to the performance requirements, for a RV-7 to get an amateur built aircraft certification. This also include the creation of the performance chapter of the POH.I am planning to start my test program in 10 days. Because of that I need some information and references from experienced RV-7 builders and flyers.

My RV-7 has:
a Mattituck TMX O-360 engine(180BHP/132KW)
a Prince Aircraft 68/78 (diameter/pitch) fixed pitch propeller (2 blades)
MTOW 1800 lbs

If you have a similar RV-7 I would totally appreciate it if you send me an e-mail with the following information:

1. Important Speeds in kts (calibrated airspeed CAS)
VS0 (stalling speed or the minimum steady flight speed obtained in a landing configuration):
__________ CAS in kts
VS1 (stalling speed or the minimum steady flight speed obtained in a specific configuration):
__________CAS in kts
VX (speed for best angle of climb):
__________CAS in kts
Vy (speed for best rate of climb):
__________CAS in kts
VR (rotation speed):
__________CAS in kts
Vbest Glide Range ( speed for best glide which gives you the best rang; best angle for descent):
__________CAS in kts
Vbest Glide Endurance (speed for best glide which gives you the best endurance; minimum rate of descent):
__________CAS in kts

Please let me know if your speeds are already reduced to Mean Sea Level and MTOW (like in the ?Flight Test Guide For Certification of FAR-23 Aeroplanes Part2 Appendix-1&2&3? prescribed).

2. Additional information
engine-type: _______________________________________________________________
engine manufacturer: _______________________________________________________________
propeller facts: _______________________________________________________________
best rate of climb (ROC): ________in ft/min
balked landing (ROC): ________in ft/min
glide ratio: ________
max. continuous power rating: _______RPM
max. power rating: _______RPM
Special modification which has relevant effects on the aircrafts performance (if applicable):
_______________________________________________________________

My E-mail address [email protected]
It is also welcome if you directly send me the performance parts of your POH. Thank you very much for your efforts.


Moreover I have several questions which we can discuss within this thread:
1. I it corrects that a Mattituck TMX O-360 engine is equal to the Lycoming A4M?
2. Where can I get the ?Sea Level and Altitude Performance Chart? for this engine?
3. Does anybody have data referred to the efficiency for my Prince Aircraft 68/78 (diameter/pitch) fixed pitch propeller (2 blades)?
4. Do anybody has the Lilienthalsches polar diagram or any data for the NACA 23013,5 profile?
5. How can I calculate the airspeeds mentioned above theoretically? (Especially Vy ,VX,Vbest Glide Range ,Vbest Glide Endurance )

Thank you all for you efforts.
Best Regards,
Mr. Hunger

 

[scsmith]

23013,5 airfoil performance

I can help you with the airfoil and airplane theoretical predictions

For the airfoil, you can do it two ways:
First, get the book 'Theory of Wing Sections' by Abbott and Von Doenhoff

it has polars for the NACA 23012 and the NACA 23015. Take those two and average them - the NACA 23013,5 is just about half way between.

OR

You can put the coordinates into an airfoil program like Xfoil or other similar program, and generate a theoretical polar at the Reynolds number you are interested in. For the coordinates, again, average the coordinates between the 23012 and the 23015.

For the theoretical airplane performance model for your thesis, you should make a drag build-up that includes estimates for the induced drag, wing skin friction (from the airfoil polar) and fuselage form drag, cooling drag, etc.
You will have some adjustment parameters in the model, like equivalent frontal area, and oswald efficiency. You can 'tune' your prediction model to match closely the typical RV-7 top speed and best rate of climb from those data, and then you can use the prediction model to determine other useful performance.

 

[th8270s]

Thank you scsmith that solution with the polars sounds pretty easy. There is nothing which have to be considered? Just that simple!?

 

[rv8ch]

POHs

Hi,

There are some POHs here:

http://www.vansairforce.net/poh.htm

They may help. Viel Spass!

Mickey

 

[th8270s]

Hey thank you very much,

but there isn?t a POH of a RV-7. I know there shouldn?t be a big different between the RV-6 or the RV-7A, but I wanted to get at least 5 to 10 replies to average all the values and have a solid basic and references for the flight testing.

Best Regards,