Affiliations: Dept. of Mechanical Engineering and Materials Science,
Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555, Japan. E-mail:
mzaki@gpo.kumamoto-u.ac.jp | Mitsui Miike Machinery Co., LTD, 2-28 Asahi-machi,
Ohmuta, Fukuoka, 836-8588, Japan
Abstract: In the previous measurements of the aerodynamic sound generated from
an inclined circular cylinder, it is reported that the sound pressure level
(SPL) changes with the aspect ratio and the inclined angle. Therefore, we have
investigated the changes in the vortex structure of the wake considered as one
of the causes of the SPL variation. Using the low-noise wind tunnel, the
velocity fluctuation in the wake is measured to obtain the correlation length.
Moreover, the flow visualization is performed with a hydrogen bubble method and
a numerical analysis method in order to clarify how the wake structure changes
by variations of aspect ratio and inclined angle. As a result of this
investigation, it is shown that the spanwise structure of Karman's
vortex is highly influenced by the interference of Karman's vortex
with the bottom endplate, and that the influence on the spanwise structure in
the wake becomes greater as the aspect ratio decreases and the inclined angle
increases.
