Sailing efficiency optimization and experimental validation of a Petrel long-range autonomous underwater vehicle

Long-range autonomous underwater vehicles (LRAUVs) generally carry limited energy during observation missions, making it critical to enhance sailing efficiency through optimization design. Therefore, it is essential to understand the relationship between the shape parameters, motion modes, and sailing efficiency. This study proposes a LRAUV energy consumption model considering the variation in seawater density and drive loss, to obtain higher accuracy. In the optimization design, a surrogate model based on the response surface method is applied to establish the functional relationship between shape parameters, sailing parameters, and sailing efficiency. According to the optimization results, the AUV mode shows better efficiency in shallow sea, while the glider mode is more suitable for deep-sea operation. For the AUV mode, the applicable working band increases with the working time at fixed depth and/but decreases with the increase of the angle of attack at fixed depth. For the glider mode, the applicable working band increases the buoyancy compensation coefficient. The hotel load has less impact on the applicable working band for both modes. Based on the proposed method, a Petrel LRAUV with an optimized shape and sailing efficiency is developed, which can also serve as a reference for the preliminary design of other LRAUVs.