TY - JOUR ID - 106252 TI - A Numerical Study on the Aeroacoustic Radiation from a Finite Length Rotating Cylinder JO - Journal of Aerospace Science and Technology JA - JAST LA - en SN - 1735-2134 AU - Talesh Bahrami, Hamid Reza AU - Ghasemlooy, Sajad AU - Parhizkar, hamid AD - School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran AD - Malek Ashtar University, Tehran, Iran Y1 - 2019 PY - 2019 VL - 12 IS - 1 SP - 65 EP - 74 KW - : Rotating Cylinder KW - Aerodynamic Noise KW - Large Eddy Simulation KW - Ffowcs Williams and Hawkings KW - Acoustic DO - N2 - Rotating cylinders have wide applications in different areas, especially the aerodynamic area. However, the acoustic behaviors of these components have not been widely studied. The generating noise from a spinning cylinder is mainly due to the detached vortices from the leeward of the body. In this study, the large eddy simulation technique is used to simulate the flow field over a three-dimensional cylinder. In the following, the Ffowcs Williams and Hawkings equation is used to estimate the noise at the specified locations using the oscillating pressure components on the cylinder wall. The acoustic behavior of both stationary and rotating cylinders are studied. Results show that the acoustic behaviors of cylinders rotating with smaller frequencies (up to f=16f0, where f0 is the dominant detaching frequency of vortices on a stationary cylinder) are nearly the same. However, at higher rotational frequencies (24f0) where vortices are omitted, OASPL of the generated noise is reduced considerably (about 20 dB at different angles with constant radial positions, r=26D, at mid-span plane). On the other hand, when the rotational frequency is increased over this limit, the pressure oscillation on the wall becomes significant and the OASPL approaches higher values. UR - https://jast.ias.ir/article_106252.html L1 - https://jast.ias.ir/article_106252_3c8cb09c0ace4e104e74b83c4e8ccc9d.pdf ER -