Design optimization and analysis of a compact twin radial impulse turbine for wave energy conversion

• Published in: Results in engineering 2024-12, Vol.24, p.103561, Article 103561
• Main Authors: Elatife, Khalid, El Marjani, Abdellatif
• Format: Article
• Language: English
• Subjects: Centripetal radial impulse turbine; Compact twin turbine; Design optimization; DOE method; OWC systems; Wave energy conversion
• ISSN: 2590-1230; 2590-1230
• DOI: 10.1016/j.rineng.2024.103561

•Investigated and optimized centripetal radial impulse turbine designs for maximum efficiency in the direct operating mode.•Conducted a thorough performance analysis, comparing centripetal turbines with and without inner guide vanes (IGV).•Demonstrated the centripetal turbine's significant superiority, achieving a notable 40 % improvement in efficiency in the direct mode.•Recognized challenges, including undesirable negative torque in the reverse mode, urging further research for optimal turbine performance. The present study aims to analyze the design optimization and the performance of a novel Compact Twin Radial Impulse Turbine for wave energy conversion in an Oscillating Water Column (OWC). This twin turbine combines two-bidirectional radial impulse turbines assembled back-to-back, that should operate in an OWC system in a centrifugal or a centripetal mode. In the present work, the turbine operation has been favored in the centripetal mode (Direct), that is commonly adopted in radial turbines for high performances. The turbine performances have been evaluated by performing 3D numerical simulations for viscous, incompressible and steady flow with the ANSYS CFD tool. The Design of Experiments (DoE) method has been implemented for the turbine geometry optimization. The study looks at the influence of inner guide vanes (IGV) on the overall turbine performance, providing insights into the turbine performances. For this purpose, two turbine designs A and B, respectively, with and without IGV have been evaluated. Better results have been obtained in the absence of the IGV. Another key aspect of this research involves a comparative analysis between centripetal and centrifugal turbine modes, underscoring the advantages of the former. A peak efficiency around of 81 % is achieved for the centripetal case, marking a significant improvement of approximately the double with respect to the centrifugal case. In addition, the comparison between the present Twin turbine and a conventional bidirectional turbine developed by the same authors has revealed an increase of about 50 % in the maximum efficiencies and 25 % in the average efficiencies.