A two-step fluid–structure approach for the vibration analysis of flexible propeller blade

In this paper, a numerical approach able to evaluate the sound power emitted by a non-cavitating flexible marine propeller blade is proposed. With asymptotic expansions and order of magnitude analysis, two main phenomena are identified: the so-called propulsion and vibroacoustic phenomenon. The propulsion phenomenon is nonlinear and models the lift generation along the blade. It creates a pre-stress and a pre-strain on a deformed configuration on which the blade vibrates and emits sound waves. The vibroacoustic phenomenon is linearized and has no retroaction on the first static phenomenon. This simplified model allows to solve the fully coupled fluid–structure system in order to compute the radiated noise of a pre-stressed blade.