Study on the vibroacoustic response of compressible fluid-filled thick-walled cylinders using the three-dimensional theory of elasticity

Double-walled structures are widely used in various industries such as aerospace, marine, and automotive. Therefore, in this paper, the sound transmission in these structures is investigated. Due to the influence of rotation and shear parameters by increasing the thickness of the cylindrical shell, the Newton-based three-dimensional theory of elasticity is used. In order to solve the governing equation of motion for a cylinder, it is assumed that the displacement field is the sum of the gradients of a scalar potential field and the curl of a vector potential field. As a result, the shell motion equation becomes two separate wave equations, which solve the displacement field. To confirm the obtained equations, the present results are compared with the results of other researchers in this field that have been obtained with other theories such as classical shell theory. Finally, the effect of various parameters such as properties and thickness of the fluid layer, Mach number, and material of the cylinders are investigated. The results show that in double-walled structures with the air gap, the acoustic impedance (the speed of sound multiplied by density) of the fluid is the main and effective factor in sound control. Any fluid with more Acoustic impedance behaves better in sound control and improves sound transmission loss.