Energy-saving optimization for spacing configurations of a pair of self-propelled AUV based on hull form uncertainty design

Abstract

This paper presents a spacing configuration-based energy-saving optimization approach for a pair of AUVs to achieve minimum resistance through the hull forms and propeller interactions. The traveling resistance is relevant to hull lines optimization design, which uncertainties exist in design variables need to be considered seriously. A reliability analysis based on the first-order reliability method demonstrates that the engineering quality is not acceptable; thus, the design for six sigma was performed with uncertainty optimization to improve the design levels. Two body force models, RANS-UT and RANS-HO, were used to represent the propeller as an axial and a tangential momentum source term. The results highlight that the radial thrust distribution has a significant impact of the propeller performance. For a pair of AUVs, the energy consumption of the fleet is classified into six zones depending on the spacing configurations with a longitudinal offset and transverse separation. This study details and categorizes the relevant sources of the drag reduction and provides the most effective fleet configuration for the optimal energy profits to validate previous experimental results. Based on energy considerations, the optimal fleet configuration is determined to show excellent adaptability and reliability to provide insights for decision makers.