Tom Kyler
New Member
I know this is "homebuiltairplanes.com" and not "homedesignedairplanes.com"; however, this section is here 
I'm wondering if there are any experienced (and patient) AVL (Athena Vortex Lattice) users here? Disclosure. I'm a ME designing/engineering my own aircraft and fumbling my way through AE with lots of gaps in my knowledge I'm trying to fill, so I do not quite have the same aero foundation an AE would, but I do speak a bit of AE gibberish...and unforuntaely, I'm too old and don't have the time to go back for an AE education.
Anyhow, I'm working through my wing planform/layout and wanting to analyze, with AVL, a few variations of the 3D wing/flaps etc. With regards to AVL.....when looking at a simple, AVL sample file...unless I'm just not seeing the obvious, I see no input regarding any type of initial section Cl....and my mind is struggling to comprehend how the VL method could calculate the CL of the entire 3D surface with "no knowledge" of a 2D section Cl?; HOWEVER...and perhaps this is my real question. The AVL manual gives an example using the phrase: "(setting a CL constraint of 0.7).....will make alpha be implicitly constrained by the condition CL = 0.7". So does the reverse hold true? such that if a Alpha of 0.0 (default) is given, some Cl is assumed and indeed required for the calculation? I guess I'm not seeing this "implicit relationship".... Anyhow..trying to get out of the fog one step at a time. Anybody with radar, a radio, insight and some time is appreciated.
I'm wondering if there are any experienced (and patient) AVL (Athena Vortex Lattice) users here? Disclosure. I'm a ME designing/engineering my own aircraft and fumbling my way through AE with lots of gaps in my knowledge I'm trying to fill, so I do not quite have the same aero foundation an AE would, but I do speak a bit of AE gibberish...and unforuntaely, I'm too old and don't have the time to go back for an AE education.Anyhow, I'm working through my wing planform/layout and wanting to analyze, with AVL, a few variations of the 3D wing/flaps etc. With regards to AVL.....when looking at a simple, AVL sample file...unless I'm just not seeing the obvious, I see no input regarding any type of initial section Cl....and my mind is struggling to comprehend how the VL method could calculate the CL of the entire 3D surface with "no knowledge" of a 2D section Cl?; HOWEVER...and perhaps this is my real question. The AVL manual gives an example using the phrase: "(setting a CL constraint of 0.7).....will make alpha be implicitly constrained by the condition CL = 0.7". So does the reverse hold true? such that if a Alpha of 0.0 (default) is given, some Cl is assumed and indeed required for the calculation? I guess I'm not seeing this "implicit relationship".... Anyhow..trying to get out of the fog one step at a time. Anybody with radar, a radio, insight and some time is appreciated.
