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Recently I found a paper about incorporating corrugated skins in aircraft called 'Corrugated composite structures for aircraft morphing skin applications' by C. Thill, J.A. Etches, I.P. Bond, K.D. Potter and P.M. Weaver

Source: Paper PDF

The paper talks about how the application of corrugated skins might provide benefits in morphing skins. The paper mostly talks about the structural benefits, as requiring less force to change the shape. Even if the structure might be covered with an aerodynamic surface, I'm still interested in the aerodynamic properties of a corrugated surface.

If there's a wing surface with a corrugating perpendicular to the flow, as shown below (flow coming from the left).

enter image description here

Image taken from Paper PDF

How will such a surface incluence the effectiveness of non-corrugated ailerons?

I image such a surface would lead to a much thicker boundary layer, thereby greatly reducing aileron effectiveness.

I'm mostly interested in large corrugations(~50mm) and low speeds(~80km/h). I'm not asking about the lift generation of the surface itself, only the effect on a non-corrugated aileron.

ROIMaison
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  • As I read the paper, the corrugated element is covered by an elastic membrane that serves as the actual surface skin. – Wirewrap Nov 30 '16 at 14:10
  • It mentions: "It is also planned to consider the aerodynamic consequences of having a corrugated wing profile at various Reynolds numbers." so it seems they are having some corrugated surface. – ROIMaison Nov 30 '16 at 14:23
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    Sighardt Hörner to the rescue: Look here for data on the drag of grooves orthogonal to the flow direction. This is a non-starter with the dimensions and speeds you think about. Only covering this with a flexible skin will make this tolerable. – Peter Kämpf Nov 30 '16 at 16:59
  • @PeterKämpf Thanks for the pointer. However, Hoerner talks mostly about the drag development, whereas I'm more interested in the flow development. What kind of flow structures can I expect, and how will these influence anything that's behind the corrugated surface? – ROIMaison Dec 01 '16 at 13:25
  • @ROIMaison I'm speculating here, but expect oscillating separations (like von Karman streets) at the trailing edge. This will give you non-centering control surfaces with oscillating forces. No problem for hydraulic actuation, but not advisable for manual control. Still, flutter can be expected in either case. – Peter Kämpf Dec 01 '16 at 17:59
  • Yes the skin will be covered by elastomeric material to maintain the aerodynamic profile. However, someone studied the aerodynamics of corrugated panels. Please check this paper: https://arc.aiaa.org/doi/abs/10.2514/6.2014-2724 – Ralf Sep 19 '17 at 14:58

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