Parametric study and Multi-Objective optimization of a ductless Archimedes screw hydrokinetic Turbine: Experimental and numerical investigation

Aiming to prolong the duration of detection equipment deployed in deep water, a new type of hydrokinetic turbine with good self-starting ability should be developed to harness low-speed current energy in such deep -water scenarios. In this study, a novel ductless Archimedes screw turbine is proposed to improve the system's startup performance for low-speed current applications. An experimentally verified numerical method was used to investigate the parametric sensitivity of several key geometrical parameters. Strong interaction effects be-tween the lead angle and number of turns were observed. The turbine performance enhancement by increasing the number of turns can only be achieved at a large lead angle. A tradeoff between the lead angle and number of turns is necessary for the optimization design of the ductless Archimedes screw turbine. Multi-objective opti-mization was performed on the ductless Archimedes screw turbine to improve its self-starting ability and power coefficient by using the central composite design, the radial basis function neural network, and the non -dominated sorting genetic algorithm. Water flume experiment results showed that the maximum power coeffi-cient and static torque coefficient of the optimized ductless Archimedes screw turbine can be improved by 36.7% and 143%, respectively, with respect to the initial design. These results indicate ductless Archimedes screw turbines are suitable for low-speed current applications in deep water.

Automated summary

A new type of ductless Archimedes screw turbine is proposed to improve the startup performance of low-speed current systems. The study investigates the parametric sensitivity of key geometrical parameters using an experimentally verified numerical method. Multi-objective optimization is performed to enhance the turbine's self-starting ability and power coefficient. Water flume experiment results demonstrate significant improvements in the optimized turbine's performance.