カルマン渦放出における円柱表面上の圧力変動と後流速度変動の関係調査

抄録

A numerical simulation was performed in order to investigate the relationship of the pressure fluctuation period on the surface of a circular cylinder and the velocity fluctuation period of the circular cylinder wake in the Karman vortex shedding. The used calculation method is a vortex method. The lift coefficient was calculated in quest of the pressure coefficient on the surface of a circular cylinder, and it determined for the fluctuation period of the lift by time progress. The velocity of a wake was found with the velocity probes prepared behind the circular cylinder. The numerical simulation was performed about Reynolds number 500, 5000, and 50000. Those relationships were clarified by comparing the fluctuation period of a lift with the velocity fluctuation period of wake. The pressure fluctuation waveform was a waveform similar to a sign wave. The velocity fluctuation waveform was a peculiar waveform. As for waveform analysis, direct measurement of the wavelength was performed. As a result of analysis comparison, the period of lift fluctuation and the period of velocity fluctuation are not in agreement, when the most. However, it was found in the particular place that it is in agreement. It was proved that position picking of a hot wire probe carried out by previous study is proper.