Status of Propeller Noise Prediction Methods for General Aviation Aircraft

Desenvolvimento de um sistema de sopro para uma configuração pilone-hélice pusher com o estudo dos fenômenos aerodinâmicos e aeroacústicos associados

“…There are also dipoles related to vortex shedding, which increases the broadband no ise. Finally, the quadrupole sources are related to the turbulence leveis at the tlow leaving the trai ling edge, and are also responsible for the broadband noise (METZGER, 1995). These different noise generation mechanisms, w ith their respective characteristics are illustrated in Figure 10.…”

“…The upwash generated at the wing leading edge will tend to change the flow direction, which will no longer be parallel to the propeller axis, as shown in Figure 7. This produces a non-axisymmetric inflow, causing the blade loading to change during a revolution, leading to vibrations and noise generation (METZGER, 1995). Among the considered aspects, the biggest disadvantage for the wing-mounted configuration is the cabin noise, which would require more acoustic treatment for the aircraft, resulting in increased weight.…”