On the added mass and radiation damping of rod bundles oscillating in compressible fluids

This paper presents a theoretical analysis as well as numerical results for the added mass and radiation damping coefficients of a group of two-dimensional circular cylinders oscillating harmonically in an infinite compressible fluid. The fluid reaction force on these vibrating cylinders is obtained by solving the two-dimensional acoustic wave equation with Neumann conditions on the cylinders and the radiation condition at infinity. Numerical results show that when the acoustic wavelength is large compared with the cylinder radius, the added mass predominates over the radiation damping, and both are independent of the dimensionless wavenumber. On the other hand, when the acoustic wavelength is small compared with the cylinder radius, the radiation damping predominates over the added mass, and both are small.