Aircraft Control Surfaces to Fixed Surface Gap Question

[VN1981]

We want to minimize the gap between the control surface & fixed surface of the wing. Currently, our Control surface leading edge has round shape as shown above and the wing shroud (or closeout shroud connecting the top & bottom skins) is also similarly shaped. Our control surface acts as an elevator and hence deflects both upward and downward. We have noticed that in downward deflection, the gap between the wing and control surface grows large enough to affect performance. This issue is further exacerbated by large twists that exists towards the tip of the wing.

Since it is a conceptual study, I am free to modify the shape of control surface LE and also corresponding shroud. Just looking for some ideas on the same. Would appreciate any pointers folks.

 

[Ng2020]

Moveable surface gaps can be sealed in various ways depending on aircraft size. At the smallest simplest end, elastomeric seals or even fabrics, at the larger end of the scale, flexible or hinged panels.
However it sounds like you are able to change the leading edge profile, I'd start by looking at that, provided it does not affect performance.

 

[VN1981]

Thanks Ng2020...sealing is an option which we have not considered so far...but something to consider. Yeah, the intent of the study is to determine if LE shape affects performance...I'd start by reducing the LE round shape to a much smaller curvature...

Anyways, thanks for your replies. So far, I was not able to find out alternate shapes for control surfaces LE profile...sounds like circular one is a winner

 

[Compositepro]

The latest development work is on morphing wing shapes that have continuous outer skins that are flexed into different shapes, so that there are no gaps in any position.

 

[VN1981]

Morphing wing tech might be out of my/our ability...BTW, are there any practical examples of morphing wing being used? Definitely something to consider

 

[Ng2020]

The Wright Flyer

 

[WKTaylor]

NOTE. I believe Your use of terms in the problem definition is non-standard... and I'm confused by Your problem elements.

As I 'hear Your issue'... this sounds really like 2-major/spearate problems…

Torsional/bending wing-stiffness [or lack-of-stiffness] for control-forces reactions and...

Control-surface-to-wing/stabilizer structure... 'gap', 'fair' and 'seal' for consistent control surface power/moment/min-drag.

Also, in the 'real-world' you may need to be wary-of [concerned-about], the effects of weather [IE: moisture/rain/snow/ice/abrasion-erosion, etc] and maintainability [IE: degree of difficulty access/alignment/fastening, etc] and flutter or random/tramp-vibrations and internal-structure load reactions due to control actuation and feed-back.

NOTE. The design of control surfaces interfacing to wing/stabilizer structure has been addressed in various NACA or NASA reports... lots of ways to accomplish what You are asking about... but, I'm drawing blanks about which-ones... and no-time to search for You.

Just random thoughts...

Regards, Wil Taylor
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