抄録
In the present paper the attention is focused on the characteristics of aerodynamic sound radiated from tandem finned cylinders exposed to cross-flow. Several spacing ratios between the tandem finned cylinders ranged from 1.3 to 6.8 are tested for a Reynolds number of 1.7×10^5. We measured the spectrum of SPL and flow velocity for bare and finned cylinders with the fin pitch ratio of 0.16. As a result, we found that the peak SPL and Strouhal number of vortex shedding for the tandem finned cylinders depend on the cylinder spacing ratios as well as those for bare cylinders. The peak SPL for the tandem finned cylinders decreased rather than that for bare cylinders. This suggests that the fins suppress the aerodynamic sound for the tandem cylinders with spacing ratios ranged from 1.3 to 6.8. Strouhal numbers were calculated by using the measured values of peak frequency and the equivalent diameter of finned tube. The Strouhal number of tandem finned cylinders agreed well with that of tandem bare cylinders for large spacing ratio. However, as the cylinder spacing ratio decreased the Strouhal number closed to 0.18 which was larger than the case of bare cylinders.
