Calling Fubar512

[FrankD]

First, please accept my apologies for using the forum in a such way but you cannot receive any new messages, so here is my "private" message.

Hello Fubar,

 

while initiating myself to the arcane of the FM, several posts you wrote are very helpful and I want to thank you for that.

 

I would like to know if the methodology you describe here is still what you would recommend? Especially if the the percentage you apply for inner and outer wings fit all shapes of wings.

 

Also, could you please guide through the CL calculation process? Mostly, what is N and what speed should I input?

 

Thanks in advance and best regards

Edited March 19, 2011 by FrankD

[FrankD]

Did I say anything wrong?

Edited March 21, 2011 by FrankD

[Fubar512]

Did I say anything wrong?

 

No offense, but did it ever occur to you that perhaps people have real lives outdside of simming?

 

Number one, percentage of Cla divided among wing panels is arbitrary, in a common-sense sort of way. Inner wing panels generally have a deeper chord than outer panels, and this is where common sense comes in. What do you think creates more lift, an A-4's (or F-4, or MiG-21, or F-15, or an Su-27's) outer wing panel, or the inner wing panels? An Israeli F-15 once landed with a mere stub of a wing remaining....what does that tell you?

 

As for which Mach level to use when calculating CLa, again, that's common sense. TK uses Mach 0.4...or you can use Mach 1.0, or Mach 0.05....remember that there are CLa Mach tables. Common sense at work, yet again.

[FrankD]

No offense taken, I do have a life outdside of simming too and that's why being guided by people that been there done that is that helpful.

You are usually so prompt to answer to such questions that I really wondered what I did wrong this time, simply.

 

Please accept my apologizes if it did put you under pressure.

Thank you for your answer anyway.

About the Mach level to use when calculating CLa, I'm sticking with the "standard" 0.4 as I don't see good reason to not.

Thanks to your previous posts, the CLa calculation is not much of an issue, the part I'm bothered with is the CL calculation process, especially what is N and if the speed (in m/s) to use is the standard Mach 0.4.

 

 

Best regards

Edited March 22, 2011 by FrankD

[Fubar512]

They have little or nothing to do in this series, so I don't use them.

 

In theory, one can extrapolate CL0 from the CL value, but since there's no provision for calculating (or even directly inputting) data for the various airfoil types, I find it a moot point.

 

Creating a precise V-N curve, and applying it to the series, is likewise moot. Try it, and see what happens

 

This should be of help: http://adg.stanford.edu/aa241/structures/vn.html

Edited March 22, 2011 by Fubar512

[FrankD]

Thank you Fubar512, your experience is a real beacon here.

 

Gonna read the page you linked, then read it again, and eventually try and see.

 

 

Best regards