Control method of line spectrum excitation force for pump-jet propeller: Random unevenly spaced rotor blades

The control of the excitation force of pump-jets is of great significance for the stealth performance of submarines. In a previous study, the authors found that the sinusoidal unevenly spaced rotor blades (SUSR) can control the excitation force of the rotor, but the suppression effect is limited by the low degree of freedom. This paper proposes random unevenly spaced rotor blades (RUSR) with higher degrees of freedom, achieving twice the suppression effect of the SUSR. A method for batch generation of RUSRs is proposed in this paper, and a large number of RUSRs are generated. The numerical simulation study was carried out by selecting the RUSRs with better suppression effects through theoretical methods, and the numerical simulation method used was improved based on the previous study. The RUSR also has an impact on the excitation force of the duct. The conclusion of this paper has guiding significance for the low excitation design of pump-jets and has the potential to promote the use of unevenly spaced rotor blades in the field of pump-jets.