Fluctuation characteristics of hull surface force of a four-screw vessel in oblique flow

Abstract

To study the influence of oblique flow on propeller fluctuation pressure characteristics of a four-screw vessel, the wake field and self-propulsion performance are calculated and analyzed utilizing computational fluid dynamics simulations. The characteristics of the wake field and propeller fluctuation pressure under different drift angle consisting of 0°, ±10°, and ±20° are compared and discussed in detail. The results show that negative drift angle affected the wake field of inside propeller more severely due to the generation of bilge vortex. The mean values of inside propeller fluctuation pressure are about 30% larger than those of the outside one, while the amplitudes of fluctuation pressure are reversed. The mean values of propeller fluctuation pressure experience a gradual decrease from β = −20° to 20° with an exception of inside propeller at β = −20° condition. The fluctuation amplitude of outside propeller is more affected by oblique flow due to the influence of oblique flow on flow separation point.