关键词: 对转舵桨, 计算流体力学（CFD）, 敞水试验, 空泡试验

Abstract: The contra-rotating rudder propeller has the characteristics of good maneuverability and high propulsion efficiency, which is usually applied in ship types, such as science research vessels and offshore engineering ships. The open-water characteristics of the contra-rotating rudder propeller are simulated by using the improved delayed detached eddy simulation (IDDES) method, with comparative analyses based on the model test results. The results show that the numerical simulation errors of the thrust coefficient and the torque coefficients of the propulsion unit at the design point are within 3%. It is observed that the rudder angle has smaller impact on the open-water characteristics of the front propeller but larger impact on those of the aft propeller based on the open-water tests under different rudder angles. The transverse force of propulsion unit is 0 at the rudder angle of 2.5° in the current case. The influence of the strut on the tip vortex of the front propeller is studied through the cavitation model test. The cavitation is significantly enhanced when the tip vortex of the front propeller meets the blades of the aft propeller or the tip vortex of the aft propeller. Based on the interaction of all components of the contra-rotating rudder propeller, the induced velocity correction coefficient is introduced to transform the design of the blades of the contra-rotating rudder propeller into the design of the blades under the given incoming flow condition.

Key words: contra-rotating rudder propeller, computational fluid dynamics (CFD), open-water test, cavitation test