Propulsion performance of large-scale ship model in real sea environment

In recent years, under the advocacy of ITTC, large-scale model test technology has garnered significant attention from researchers all over the world. Increasingly sophisticated test equipment and a large amount of experimental experience have promoted the development and improvement of test technology. Here, a 25 m long bulk carrier model was built as the research object. The self-propulsion test about propulsion performance in real sea environment was conducted in the coastal waters of northern China. The manoeuvrability test proved that the designed ship model integrated system was reliable. The effects of complex wake field environments on the propulsion performance were studied using the equal thrust and equal torque methods. The results indicated that the complex wake field environment causes the torque to increase by 2%–11%, and the thrust loss ranges from 3 to 15%. When the propeller was operated at a high rotating speed, the torque and thrust in the oblique wave tended to decrease by 1–3% compared to the propulsion performance in the head wave. In addition, the more severe sea state caused the propeller torque to decrease and the thrust to increase.