Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 07, 2019 - November 08, 2019
It has been confirmed that the taper cylinder has an effect of reducing the Aeolian tone radiated as compared with the circular cylinder. In this paper, static pressure fluctuations and velocity fluctuations in the wake of a tapered cylinder were measured using a conical tip type static pressure tube probe and an x-type hot wire probe, and the flow structure and static pressure fluctuations in the wake of a tapered cylinder were clarified. The static pressure fluctuation power spectral density was also clarified. The Reynolds number based on the diameter of the mid span of the tapered cylinder and the uniform flow velocity is 2.65×104. At the position of x'/D = 2.0 to 5.0, the static pressure shows a smaller value as the taper ratio increases. It was found that in the tapered cylinder, the dead water region was long and the rolling up of the shear layer was on the downstream side, and the static pressure fluctuation decreased. Also, it was considered that the von Karman vortices did not occur in the wake of the tapered cylinder and it was observed of decreasing of the peak level in the sound spectra. Comparing the peaks level, it was confirmed that TC1 was reduced by 24.7 dB, TC2 by 15.6 dB, and TC3 by 9.7 dB compared to the circular cylinder.
