Extending the aircraft flight envelope by mitigating transonic airfoil buffet

TL;DR

This paper demonstrates experimentally that porous trailing edges can significantly reduce transonic airfoil buffet, potentially extending aircraft flight envelopes and decreasing noise emissions, thus enhancing safety and environmental sustainability.

Contribution

The study introduces the use of porous trailing edges as an effective method to mitigate transonic buffet and reduce aircraft noise, a novel approach in aerodynamics.

Findings

Porous trailing edges substantially attenuate transonic buffet.

Application of porous edges reduces aerodynamic unsteady loads.

Porous edges also decrease aircraft noise emissions.

Abstract

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, i.e., its operational limit in the high-speed regime, is usually fixed by the occurrence of an 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 experimentally 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.