Characteristics of wings embedded in the fuselage

[K Yoshi]

Hello everyone.
Most of the examples in OpenVSP have the wings encroaching into the fuselage.
When evaluating wing performance in VSPAERO, I do not believe that keeping the fuselage displayed or NoShow will produce accurate results at Geometry Set:Shown.
I think the wing roots should be offset just to the sides of the fuselage to prevent the wings from digging into the fuselage, what are your thoughts on this?

Thanks,

[Mike Vivaldi]

If you perform an aero analysis or run compgeom VSP will remove the intersections inside the fuselage in the output geometry. You may need to do an offset for an accurate VLM analysis

[K Yoshi]

Hello Mike, It's a relief to find out that the area where the wing and fuselage intersect is not calculated.
Wings are usually designed to obtain the required lift, so if the projected area that intersects with the fuselage is large, the error from theoretical calculations becomes large.
With these things in mind, I will adjust the YLoc value of the wing geometry. Thank you.

[Rob McDonald]

Just leave Yloc=0 unless you have a compelling reason.

It works better for thin-surface aero to have the wing connect through the center line.

Thick-surface aero does appropriate trimming.

Leaving Yloc=0 makes it easier to deal with parametric changes later -- if you have a tapered fuselage and move the wing fore/aft,  or if you change the fuselage diameter, or whatever, you don't have to come back and tweak or adjust the wing's YLoc.

If you fine tune the YLoc to just barely bury the root of the wing to the fuselage, then you've created an overall system that is fragile to parametric variations.  However, if you just bury the wing to YLoc=0, it is much more robust to later parametric variations.

Rob

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[K Yoshi]

Hello Rob, You're right, my design requires me to modify the YLoc values ​​every time I adjust the geometry relative to one another.
I now understand why many of the designs I see on YouTube and other sites are designed with YLoc=0. Thank you very much ;)