With the development of numerical tools used to simulate fluid-structure interactions phenomena, investigations on hydrodynamic damping are now more accessible and the studied cases are more flexible. The aim of the present study is, at first, to analyze the hydrodynamic damping on a simple blade placed in water using ANSYS and CFX codes to simuate the fluid-structure interaction. The influences of the velocity, the amplitude of the vibrations and the material properties are investigated. Secondly, by placing many adjacent blades vibrating, firstly, in opposite phase and then in phase, the influence of the vibration phase on the hydrodynamic damping value is analyzed.