Structural and dynamic analysis of tapered mast bladeless wind turbines using FEA and CFD for renewable energy generation

The present analysis investigates the possibility of using a tapered mast profile for bladeless wind turbines (BWTs) to enhance the function of extracting wind energy through the phenomenon of vortex-induced vibrations. Conventional HAWTs which remain the most efficient are however, costly in maintenance, mechanically complicated and rather unfavourable to the environment. To overcome these challenges a prototype BWT with a 0.6 m tapered mast was developed for the currents using mild steel and hollow square steel sections. Wind tunnels were also used to compare stress distribution, structural deformation and vane vortex shedding for the building at different wind speeds. The maximum calculated equivalent stress on the mast was 1.63 ´ 105 Pa with the total deformation achieving 1.732 ´ 10‒6 m at a wind speed of 4 m∙s‒1. The tests have represented an independent check on mast dynamics using recorded wind at an average of 7 m∙s‒1 and have quantified the observed oscillations marking validity of the dynamic behavior observed through simulations. Piezoelectric sensors deployed to measure mechanical stress produced voltage responses of 7.68 mV, 28.865 mV and 44.915 mV at wind velocities of 5.5 m∙s‒1, 6.1 m∙s‒1 and 7.8 m∙s‒1 respectively. Findings show that wave amplitude of the oscillations increases with wind velocity and concomitantly voltage generated. The study highlights the potential of tapered mast geometries in improving structural efficiency and energy output.