Structural Modification and Optimization of AlSi7 Mg0.6 Alloy Based Rotor for Wave Energy Harvesting

Conventional navigational buoys are powered by solar panels which need to be maintained frequently, thereby increasing the cost of maintenance. Additionally, solar panels are dependent on the availability of sunlight which is limited to a certain time of the day. An alternative approach is to use wave energy based navigational buoys which depend on the energy generated by surface waves in the ocean. For large-scale exploitation of the offshore wave energy source, navigational buoys require turbines which should be able to withstand varying pressures while simultaneously react to the pressure difference of the waves, thereby generating electricity. In this paper, an optimized design for unidirectional impulse turbine previously used in a Backward Bent Ducted Buoy (BBDB) has been proposed. The proposed design has higher structural strength while maintaining the basic performance capabilities. It was observed that using aluminum alloy AlSi7 Mg0.6 instead of conventionally used polycarbonate material improves the structural strength of the designed turbine while maintaining it’s weight (~9 % increase) so that the problem of inertia while self initiating is kept at bay. The analysis of the rotor for the stresses was carried out using Ansys 18.2.