Propeller hydrodynamic excitation influenced by shafting whirling vibration considering different nonuniform inflow conditions: A numerical study

Abstract

The hydrodynamic excitation generated by a propeller rotating in nonuniform inflow causes the propulsion shafting to vibrate, and this vibration feeds back to the propeller hydrodynamics, giving rise to two-way coupling in the propeller–shafting system. Investigated here are unsteady propeller hydrodynamic excitation influenced by shafting whirling vibration considering different nonuniform inflow conditions. This is done using the delayed detached eddy simulation and a method that can simulate the two-way coupling between the propeller hydrodynamics and shafting rotor dynamics. First, the simulation method was introduced, and the method as well as the propeller hydrodynamic model are validated. Second, numerical simulations are reported considering two-way coupling with different nonuniform inflows. The results show that, the two-way coupling has an influence on the amplitude and phase of the excitation, while the frequency remains still. In terms of degree of freedom, the radial excitation amplitude increases by 31.65% after considering the two-way coupling. The coupling causes spatial and temporal unevenness of the propeller inflow velocity and angle of attack, accompanied by a larger fluctuation magnitude, both result in the variation of amplitude and phase in the hydrodynamic excitation and rotor dynamic response. Different nonuniform inflow influences the radial hydrodynamic excitation and the shafting orbit.