Influence of wake field on propeller exciting force of submarine

ObjectiveThe appendages of a submarine affect the wake field at the propeller disk, which in turn affects the exciting force characteristics of the propeller. Grasping the influence law of the wake field on the exciting force is helpful for the low-excitation force design of submarines and propellers. MethodBased on the Suboff Model and INSEAN E1619 propeller, the RANS method is used to numerically simulate the propeller exciting force under wake fields affected by different appendages, and the harmonic analysis method is used to quantitatively characterize the wake fields at the propeller disk. The mechanism of the linear spectrum exciting force is revealed by combining the distribution characteristics of the transient flow field of the propeller. ResultsThe results show that the distribution of each order of the harmonic components of the wake field is consistent with the distribution of a single-blade linear spectrum exciting force, and the relative amplitude of the single-blade exciting force in its main frequency is basically equal to that of a seven-blade propeller. The harmonic components of circumferential symmetrical rudders to the wake field are mainly concentrated on the fourth and eighth orders, and have little effect on the exciting force of a seven-blade propeller; however, fairwaters influence the harmonic components of the wake field and have a major effect on the exciting force of a seven-blade propeller. ConclusionThe influence of rudders on propeller exciting force is less than that of fairwaters. In order to improve the exciting force characteristics of propellers, the optimization of submarine fairwaters should be emphasized.