A finite element stress analysis has been carried out on two configurations of impulse turbine blade, hollow and solid. The hollow turbine blade has significant manufacturing advantages over the solid blade and it is an aim of the analysis to compare how well the blades support the forces exerted on them. The centrifugal and aerodynamic forces on the blades have been calculated. Safe working stresses and strains were identified and post solution checks were carried out and confirmed the order of magnitude of the finite element results. Visualisations of the finite element results are also presented. It was found that the stresses produced in both the hollow and solid blades do not exceed safe working stresses. Based on this analysis, the hollow blade variant was selected for manufacture due to its cost advantages and superior lead-time characteristic over the solid blade.
For the last two decades, Scientists have been investigating and defining different methods for power extraction from wave motion. These devices utilize the principle of an Oscillating Water Column (OWC). OWC based Wave Energy Power Plants convert wave energy into low-pressure pneumatic power in the form of bi-directional airflow. Self-rectifying air turbines (which are capable of operating uni-directionally in bi-directional airflow) are used to extract mechanical shaft power, which is further converted into electrical power by a generator. Two different turbines are currently in use around the world for wave energy power generation, Wells Turbine, introduced by Dr. A. A. Wells in 1976 and Impulse Turbine with guide vanes by Kim et al. (1988). Both these turbines are currently in operation in different power plants in Europe and Asia on experimental basis. Currently, research around the world is focused on improving the performance of both these turbines under different operating conditions.
