Abstract
A growing interest in harnessing ocean current energy for deep ocean observation platforms has been encouraged by the requirement of cost saving and wide-range deployment. A new concept of deep-water in-situ power generation system using ductless Archimedes screw hydrokinetic turbines was proposed in this study. To fill the hydrodynamic knowledge gap of ductless Archimedes screw hydrokinetic turbines, an experimentally validated numerical model was built to perform a parameter-sensitive study. Results demonstrate that interactions with the turbine's cylindrical side enable efficient operation even under yawed conditions. The power coefficients were found to be higher with yaw angles ranging from 310° to 50° and from 130° to 230° compared to the non-yawed state. To further enhance the hydrodynamic performance of the turbine, two optimization procedures were proposed: multi-objective optimization and specific optimization. An in-house Simulink model was developed to assess the effectiveness of the two optimization procedures. The results indicate that the specific optimization is better suited for practical applications when the ocean current data is available. With an optimized turbine radius of 0.15 m, the proposed deep-water in-situ power generation system can provide sufficient energy to power environmental sensors, such as temperature and salinity sensors.