空力音の発生に対する主流乱れの影響(騒音(1),一般講演)

概要

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In order to clarify the effect of uniform flow turbulence, aerodynamic sound and static pressure fields were measured in a low-noise wind tunnel with an active turbulence generator. The experimental results showed that influence of turbulent intensity for aerodynamic sound generation was not clear. However, the noise levels depended on the eddy scale of the uniform flow. The spanwise coherence length of circular cylinder depended on the scale of incoming flow. Since the spanwise scale decreased in the large-scale turbulent field, as a result, resultant aerodynamic noise also decreased. It indicated that the scale of the uniform flow dominant parameter for aerodynamic noise generation in turbulent flow fields. The phase averaged static pressure fields were also measured. The experimental results showed that the large scale eddies of the uniform flow destroyed Karman vortex. Therefore, Karman vortex disappeared when the scale of uniform flow were almost the same as the diameter of the cylinder.
日本流体力学会の論文
2007-08-06