Issue / weird behaviour when using TE Closure on blended sections.

[David Clemens]

Hello! 

I have an issue when using TE Closure in the Modify tab on blended sections. 

When blending is applied to the leading edge of this section, like making the LE curved and then using TE Closure to increase the thickness of the TE, it will cause the TE thickness to balloon weirdly but only on the section where blending was used. (See picture.) Is there a way to fix this issue? 

I also attached a VSP file where I reconstructed the issue. 

[David Clemens]

I tried using custom airfoils with a TE gap built in, and it gives me the same results as using the built-in TE Closure modify.

I'm not sure what else to try now. Any help would be appreciated!

[Rob McDonald]

There isn't really a solution at this time.

OpenVSP must interpolate the airfoils across a blended region.  It does the interpolation in a frame where the airfoils have  unit chord.  So, in that scale, the t/c of the root/tip airfoils of that blended section are very different.

OpenVSP basically creates intermediate airfoils with linearly varying t/c of the blunt trailing edge.  When those get lofted, the chord varies in a nonlinear way -- and so your dimensional thickness of the blunt te varies as it does.

Rob