Research on the design and optimization of the single-jet volute for the baseplate omnidirectional waterjet

The volute is essential for thrust generation and omnidirectional steering in the baseplate omnidirectional waterjet. The current volute design faces two challenges: insufficient documentation on design methodologies and structural complexity in widely-used three-jet volutes, increasing production challenges and costs. This paper presents an optimization of the single-jet volute design in baseplate omnidirectional waterjets to enhance performance. (1) A typical three-jet volute baseplate omnidirectional waterjet is utilized as the prototype. The improved single-jet volute is geometrically modelled and parameterized. (2)The single-jet volute design parameter space is constructed using Latin Hypercube Sampling (LHS). (3) The RANS viscous flow method is employed to obtain the propulsion performance indicators of the sample space. (4) The multilayer perceptron (MLP) neural network has been used to expand the sample space. (5)The Non-Dominated Sorting Genetic Algorithm III (NSGA-III) is used to determine the optimal volute design parameter combination. The optimized single-jet volute, simpler than the three-jet volute, exhibits superior propulsion performance. The single-jet volute reduces shaft power by 3.7 % and increases the thrust-to-power ratio F_x/P by approximately 5.1 % compared to the three-jet volute, while its simplified structure lowers manufacturing costs. The findings of this paper can serve as a reference for design optimization of this specialized propulsion system.