Study on the interaction characteristics of hull-propeller-appendages of autonomous underwater vehicle based on unsteady conditions

In order to improve the hydrodynamic performance of autonomous underwater vehicle (AUV), a new method is proposed to study the AUV hull-propeller-appendages interaction in coupled mode, considering the coupling effect between the AUV hull, propeller and appendages, and to predict the self-thrust point. Based on the Reynolds mean Navier-Stokes (RANS) solver and the RNG k−ε turbulence model, the hydrodynamic performance of the propeller and AUV is predicted. The error between the predicted results and the experimental results is within 5%, which verified the correctness of the modeling method based on CFD. Finally, the thrust and torque generated by the open-water propeller and the propeller after the boat, the hydrodynamic characteristics of the naked AUV and the AUV with appendages, and the interaction between hull-propeller-appendages under different working conditions are studied. Experiments are carried out in Qiandao Lake, Zhejiang Province, China. The numerical simulation results of AUV at 1.76 m/s are compared with the experimental results of 1.5 m/s, and the correctness of the proposed interaction method is verified. The research results not only provide theoretical guidance for the design and operation of AUV, but also have important significance for improving the performance and reliability of AUV in complex underwater environments.