MAE Deparatment - PG Seminar -   Airframe Noise Reduction by Local Application of Porous Material

Noise produced by Aircraft can be a significant nuisance for the community around airports. Airport expansion plans are increasingly hampered by stringent noise regulations. Besides the noise produced by aircraft engines, airframe noise is important in certain flight phases (e.g., landing phase). Airframe noise can be defined as sound generated by the interaction between a turbulent flow and the aircraft’s geometry, e.g. landing gear noise, flap side-edge noise, or noise generated at a wing’s trailing edge. One of the challenges is a solution of the potential conflict between the growth of air transportation systems and the required noise reduction. One approach for such noise reduction can be to locally use porous materials on the trailing edge of a lift-generating wing. In this presentation, the used numerical prediction method is concisely presented followed by the local application of porous material with the aim to reduce of the sound produced at the wing’s trailing-edge. Local application here means substituting the latter part near the wing’s trailing-edge with a porous inset. Several numerical examples will illustrate the performance and limitations of the suggested noise reduction method. If time permits, also other passive means of noise reduction will be discussed, e.g., finlets.