Abstract
A numerical study of the aerodynamic noise generated when an airfoil/blade in a uniform flow is excited by an oncoming vortical flow is reported. The vortical flow is modelled by a series of flow convected discrete vortices representative of a Karman vortex street. Such noise generation problems due to fluid-blade interaction occur in helicopter rotor and turbomachinery blades. Interactions with both rigid and elastic airfoil/blade are considered. Under a vortical excitation, aerodynamic resonance of the airfoil/blade at certain excitation frequencies is found to occur and loading noise is generated due to the fluctuations of the aerodynamic loading on the airfoil/blade. For an elastic blade, due the occurrence of structural resonance incited by the flow-induced vibration of the airfoil/blade, a stronger loading noise is generated. The associated thickness effect due to the airfoil/blade vibration is extremely weak. The magnitude of the noise was found to depend on the frequency of the oncoming vortical flow and the geometry and rigidity of the blade.
| Original language | English |
|---|---|
| Pages (from-to) | 217-237 |
| Number of pages | 21 |
| Journal | Journal of Sound and Vibration |
| Volume | 245 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 9 Aug 2001 |
ASJC Scopus subject areas
- Condensed Matter Physics
- Acoustics and Ultrasonics
- Mechanics of Materials
- Mechanical Engineering