Literature survey - wing surface roughness effect on performance

[MattH150197]

Homework Statement

I am currently trying to do a literature survey on my project task 'effect of wing surface roughness on wing performance'. I have been struggling to find many research papers that are of a similar experiment to mine, however i have come across many that investigate the effect of ice build up on a wing, should i use this? and have been reading through the conclusions to try and find where i could progress from their experiment and investigate some problems they may have came across or areas they had not researched but all the conclusions seem to pretty straight forward that surface roughness on a wing leads to a decreased L/D ratio. It is really annoying me that this part is taking me so long, would really appreciate some ideas. Thanks.

 

[rcgldr]

The issue with ice build up it that it tends to form on a wing in a manner that reduces the lift. If angle of attack is increased to compensate, the ice formation will continue to further reduce lift, until the lift to drag ratio goes below what is needed for an aircraft to maintain altitude.

In the case of gliders, the surface of a wing can be too smooth, resulting in a separation bubble near the transition from laminar flow to turbulent flow (where it usually reattaches), and form/profile drag is increased due to the separation bubble. By roughing up the surface a small amount (like 600 grit sandpaper on a fiberglass wing) or even using turbulators, the transition to turbulent flow occurs earlier, eliminating or reducing the size of the separation bubble:

https://en.wikipedia.org/wiki/Turbulator

 

[CWatters]

I haven't looked for papers but I'd be surprised if a lot of research hadn't been done.

When I flew gliders our club had one glider with a relatively thin wing section. This meant that when wet the increased stall speed could get a bit too close to the maximum winching speed for comfort. For that reason the wing was always dried carefully if it got rained on.