Unsteady wall pressure characteristics of a 90 degree elbow in high Reynolds numbers

Iwamoto, Yukiharu*; Yamano, Hidemasa   

Wall pressure measurements were conducted for a 90 degree elbow of which the axis curvature coincided with its inner diameter (125 mm). Results showed that distributions of fluctuating normalized pressures obtained here and those made by Shiraishi et al. (2006) for the Reynolds number of 3,250,000 coincided within 0.02 of the dynamic pressure. The peak intensity having the Strouhal number of 0.5 was quantitatively in accordance with that of the data obtained in the experimental setup that Shiraishi et al. used (Yamano et al., 2011), suggesting that the law of dynamical similarity could be applied with regard to this oscillation. Cross correlations of pressure fluctuations showed that the pressure fluctuation having the Strouhal number of 0.5 propagated as a planar wave with the bulk velocity.