充腹構造断面の空力振動現象に関する研究

Abstract

In this study, the effects of turbulence on galloping were investigted from the frequencyeffect of turbulence point of view. Two 2-D rectangular cylinders with slenderness ratios 1 (B/D=1, B: chord length, D: height of section) and 2 (B/D=2) were used and the steady lift forceand an aerodynamic response were measured in grid-turbulent flow and a pulsating sinusoidalflow. As a result, it is sujested that the higher frequency fluctuating components of turbulenceintensifies the entrainment effect of separated shear layer around the body, and the comparativelylow frequency fluctuating components of turbulence which is correspponeding to "shear layer in-stability enhancement frequency region" which would generate a vortices on a body side surfacewhich sometimes interact with Karman vortices, have few significant effect on steady lift forceand galloping response.