Abstract
The effect of twist serrated fin around a bare tube on aerodynamic noise was experimentally investigated. This fin is mounted spirally around a bare tube surface and has same geometry as those actually used in boiler tubes. We measured the spectra of sound pressure level of noises generated from fin tubes with various fin pitches. As a result it was made clear that Aeolian tone induced by Karman vortex shedding was observed in the case of a fin tube, although the complicated fin mounted around a bare tube. However, as the pitch of the fin decreased, the peak level of spectrum of sound pressure level decreased.
