Questions on XFLR5

[rosco]

Wow, thanks Raptor22 for helping me with these questions.

O.K.

1.......In the "define a polar analisis", is the "mom. ref. location" where you put your intended C.G.?
2.......Pic1 has a flying wing in it with the elevators up. What is the red arrow indicating?
3.......What is the green arrow indicating?

4.......I guess that pic2 is indicating the opposite?

O.K. here's the tricky bit. The next plane is a little unconventional, as the elevator is so far forward that its elevator is surposed to act like a canard does!

5......In pic 3 The elevator in this is up...what is the red and green arrow indicating?

6......In pic 4, The elevator in this oic is down...what is the red and green arrow indicating? Also, why is the green arrow changing position? I am guessing that it has somthing to do with XCP in the bottom right? Is that the position of the 'centre of pressure'?

7......In pic5, there is no elevator input, what are the arrows indicating here?

I hope that this is not too much :o
Thanks again
rosco

[Bg~]

Red arrow: pitching moment (note that it's curved)
Green arrow: lift, and I think it's located at the center of pressure (I could be wrong). It's the sum of the green lift distribution.

If you sweep through a range of alpha's and then check the 'Anim' box, you will see how they change with alpha.

[rosco]

Thanks for that. I appreciate your answers.

I've had a bit more of a think and have another question.

Is the location and intensity of the red arrow a product of the green arrow (sum of the lift distribution) acting around the 'moment reference location' (which I think is the nominated c.g.)??

cheers
rosco

P.S. Are you still able to shed some light on these questions raptor22?

or anyone for that matter :o

[raptor22]

To be honest, I'm not 100% sure about the moment ref. location. However, I am 95% sure that it would be the C.G because the cg can be though of as the natural axis around which the airplane rotates.

Yes, the red arrow would be caused by the sum of lift distribution's moments on the reference location...or the moment caused by the green arrow.

--Alex

[rosco]

Thanks again Raptor22

Do know why the position of the green arrow moves, even if the C.G. stays the same?

cheers
rosco