Sound Radiation from Finite FGM Cylindrical Shell Excited by a Rotating Load

This paper presents to evaluate the vibration and sound radiation of a finite functionally graded material cylindrical shell immersed in light and heavy fluid and excited by a constant point load continuously traveling along the circumferential direction at a rotational speed . Attention is focused on the explanation of radiation phenomena in both fluids and the FGM shell´s parameter influence of the power law index. A frequency-domain representation of the rotating load shows that its frequency content is a series of equal amplitude harmonics N. Each harmonics excites exclusively the circumferential mode N. For this rotating excitation, vibration and radiation critical speeds are identified. Extensive numerical results are also presented to illustrate the comparison of vibration and sound radiation ability in two different fluids, which show that the behaviour of the shell in water is very different from that of the one in air.