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.

The workflow and existing problems of the design of the traditional anchor system are introduced from the viewpoint of efficiency improvement and cost reduction. Based on the above problems, the integration scheme of the computer aided engineering (CAE) analysis technology is presented for the anchor system design. In the design process, the three-dimensional simulation verification of the anchor system is implemented by using the three-dimensional geometric modeling, the construction of the digital twin virtual prototype and the multi-body dynamic simulation analysis of the anchor system. The design scheme of the anchor system is then iteratively optimized to promote the design accuracy and shorten the design cycle. This technology can provide a complete set of solutions for the collaborative interaction, verification and drawing in each link from scheme design, detailed design to the production design.