Abstract: Abstract： The computational fluid dynamics(CFD) method was used to study the influence of hullwaterjet interaction on propulsion performances of waterjet to research hullwaterjet interaction mechanism needed in speed and resistance prediction of waterjet propelled vessel. The threedimensional viscous flow fields of waterjets under openwater condition and mounted on hull with different deadrise angles and trim were obtained by calculating RANS equations closed by the kε turbulence model. The creditability of numerical model and method was validated by the good agreement between calculated results and test data. The results of different deadrise angle or list models showed that the deadrise angle or list had hardly any effect on the propulsion performance of waterjet. The results of different rocker angle or trim models showed that the rocker angle and trim made the hull boundary layer change, and had a notable influence on the propulsion performance and effect factors of the waterjet. With trim angle changing from positive to negative, the utilization of hull boundary layer by the waterjet increased, so the mass flow through waterjet decreased; however, the power, thrust and head increased. Besides, the momentum velocity coefficient, energy velocity coefficient, momentum interaction efficiency and energy interaction efficiency were decreased, too. However, the waterjet counteracted the hull by producing torque to whittle the trim angle.

Key words: ship, waterjet, interaction, effect factor, computational fluid dynamics