A bit puzzled about all those "zero degree" AOA posts ?
Is that from centerline front wing to centerline stabilizer ?
If so, it only shows that you have some lift on the wing, even when the stabilizer is not lifting up nor down.
All front wings have lift at zero degree AOA (which is NOT parallel to the bottom of the wing)
Often named the "Beta" angle, which is the negative AOA the wing should have, in order to produce zero lift.
The angle of the fuselage and board means nothing (apart from parasitic drag and handling) - it is only the AOA difference between the front wing center line and stabilizer center line that matters here
Dont know if off topic or not - but I find it confusing talking about zero degree AOA without naming exactly what front wing profile that has been used.
Also a bit sceptical, IF the front wing really has zero degree AOA, as I think a few might call it "zero" if the bottom of the wing is "flat" on the table so to speak - eventhough the centerline has positive AOA, and when you add the Beta angle, you actually got loads of lift now
We need a referance point when talking A O A of wings for sure.
So what we call 0° A O A is centerline if you want.
I would agree fully that in this 0° AOA centerline that there is lift here.
we now have a referance for the rear wing using the same 0° AOA centerline
Sure we know the rear wing is mounted 180° to shown diagram.
Anyway I try to keep it simple for my garage builds.
90° strut to board and 90° strut to fuse
Because of this you measure 0° AOA centeline which is the center of the LE of wings and point of T E to the fuse parallel.
I would have no way of finding true NO lift A O A of wings in my garage.
I know you fly a production kiteboardhydrofoil, if you have a minute could you measure your wings centerlines, AOAs as compared to the fuse AND board as they are probably not 90° angles.
I also know you understand and study aerodynamic concepts, I only throw my extensive rc helicopter experience at this hydrodynamic kiteboardhydrofoil game so any and all new info much needed.
Another question for you to ponder?
Do you think when a foil flys that the rear wing is giving down force, may seem like a stupid question as it would seem that even with profile inversed that the positive AOA when flying would force it to generate lift.