Can we make commercial aircraft faster? Mitigating transonic buffet with porous trailing edges

Extending the aircraft flight envelope by mitigating transonic airfoil buffet
by Esther Lagemann, Steven L. Brunton, Wolfgang Schröder, Christian Lagemann
arXiv: arxiv.org/abs/2401.08894
In the age of globalization, commercial aviation plays a central role in maintaining our international connectivity by providing fast air transport services for passengers and freight. However, the upper limit of the aircraft flight envelope, essentially the maximum aircraft speed, is usually fixed by the occurrence of a safety-critical aerodynamic phenomenon called transonic airfoil buffet. It refers to shock wave oscillations occurring on the aircraft wings, which induce unsteady aerodynamic loads acting on the wing structure. Since these loads can cause severe structural damage endangering flight safety, the aviation industry is highly interested in suppressing transonic airfoil buffet to extend the flight envelope to higher aircraft speeds. In this contribution, we demonstrate with experimental wind tunnel measurements that the application of porous trailing edges substantially attenuates the buffet phenomenon. Since porous trailing edges have the additional benefit of reducing acoustic aircraft emissions, our findings could pave the way for faster air transport with reduced noise emissions.

[@denizkacar2704]

Really interesting, but i would have also adored having the drag data if collected to see if it is an improvement on all fronts. But i suspect as Esther described, the absorbed kinetic energy by the porous material has an effect on drag. Really interesting, and a big thanks to the university of washington and especially Steve for sharing all this educational content.

[@balajisriram6363]

I am an electrical engineer, but with a love for aerodynamics. This was just great.

[@rampy4963]

Commercial aircraft avoid flying at Mmo because of the sudden rise in transonic drag, well before transonic buffet becomes a factor. Is overall transonic drag reduced by the damping of shockwave oscillations using porous trailing edges?

[@fzigunov]

Interesting findings, but I need to say... In your presentation (and paper!) you're missing (1) the actual BOS fields, so the reader can assess the measurement quality; (2) in the presentation you don't show the PIV result (nor the velocity fields!), only presenting an argument of what you think is happening, without evidence. (3) There doesn't seem to be any assessment of your shock-detection algorithm's uncertainty, which is crucial to ascertain that what you are seeing is not just noise. Otherwise, it is a good start!

[@_NickTech]

Interesting topic, thanks for covering it

[@opencast1819]

Great work and talk Esther!

[@tyrand]

All of this went over my head.

[@rostamr4096]

Great job and very impressive..

[@ahmedkhelifa5926]

Thank you, Can you tell me what is the program you are using to teach like that?

[@Jaylooker]

I wonder how rain or snow affects the performance of a porous trailing edge. Maybe there needs to be a hydrophobic coating on it?

[@countpoolnoodleiii99]

I'm not sure I would classify selective laser 3D-Printing of large aerodynamic surfaces as something that can be easily adapted by industry nevertheless the aerodynamic concepts and solutions presented are fascinating.

[@arturoeugster7228]

Ever heard of supercritical airfoil, 2 types one by NASA, and the other is able to transition from the supersonic region to subsonic without the lambda shock. Both extend the TAS, which is different from the IAS on the shown load speed diagram. It is well known that modest suction will prevent turbulent boundary layer sepatation due to the pressure rise caused by the shock. At any rate, the shown airfoil sections are inadequate compared to the NACA super critical flat top airfoil.

[@arpandas2758]

read the paper, this is showcased on a supercritical airfoil

[@HH-yb2dv]

Hello...