Numerical study on air turbines with enhanced techniques for OWC wave energy conversion
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In recent years, the oscillating water column (OWC) wave energy converter, which can capture wave energy from the ocean, has been widely applied all over the world. As the essential part of the OWC system, the impulse and Wells turbines are capable of converting the low pressure pneumatic energy into the mechanical shaft power. As an enhanced technique, the design of endplate or ring attached to the blade tip is investigated numerically in this paper. 3D numerical models based on a CFD-software FLUENT 12.0 are established and validated by the corresponding experimental results from the reports of Setoguchi et al. (2004) and Takao et al. (2001). Then the flow fields and non-dimensional evaluating coefficients are calculated and analyzed under steady conditions. Results show that the efficiency of impulse turbine with ring can reach up to 0.49 when ϕ=1, which is 4% higher than that in the cases for the endplate-type and the original one. And the ring-type Wells turbine with fixed guide vanes shows the best performance with the maximal efficiency of 0.55, which is 22% higher than that of the original one. In addition, the quasi-steady analysis is used to calculate the mean efficiency and output-work of a wave cycle under sinusoidal flow condition. Taking all together, this study provides support for structural optimization of impulse turbine and Wells turbine in the future.
KeywordsOWC impulse turbine Wells turbine CFD endplate ring quasi-steady analysis
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- Cruz, J., 2008. Ocean Wave Energy–Current Status and Future Perspectives, 210, Springer-Verlag, Berlin.Google Scholar
- Hyun, B.S., Moon, J.S., Hong, S.W. and Kim, K.S., 2005. Design of impulse turbine with an end plate for wave energy conversion, Proceedings of the 15th International Offshore and Polar Engineering Conference, International Society of Offshore and Polar Engineers, Seoul, Korea, 1, 507–512.Google Scholar
- Kim, T.W., Kaneko, K., Setoguchi, T. and Inoue, M., 1988. Aerodynamic performance of an impulse turbine with self-pitch-controlled guide vanes for wave power generator, Proceedings of the 1st KSME–JSME Thermal and Fluid Engineering Conference, Seoul, Korea, 2, pp. 133–137.Google Scholar
- Raghunathan, S., Tan, C.P. and Ombaka, O.O., 1985. Performance of the Wells self-rectifying air turbine, The Aeronautical Journal, 89, 369–379.Google Scholar
- Setoguchi, T., Takao, M., Kaneko, K., and Inoue, M., 1998. Effect of guide vanes on the performance of a Wells turbine for Wave energy conversion, International Journal of Offshore and Polar Engineering, 8(2), 155–160.Google Scholar
- Takao, M., Setoguchi, T., Kim, T.H., Kaneko, K. and Inoue, M., 2001. The performance of a Wells turbine with 3D guide vanes, International Journal of Offshore and Polar Engineering, 11(1), 72–76.Google Scholar
- Takao, M., Kinoue, Y., Setoguchi, T., Kinoue, Y., Kaneko, K. and Nagata, S., 2006. Improvement of Wells turbine performance by means of end plate, Proceedings of the 16th International Offshore and Polar Engineering Conference, International Society of Offshore and Polar Engineers, California, USA.Google Scholar
- Takao, M. and Setoguchi, T., 2012. Air turbines for wave energy conversion, International Journal of Rotating Machinery, 717398.Google Scholar
- Thakker, A. Setoguchi, T., Takao, M., Itakura, K., Mohammad, M. and Kaneko, K., 2003. Effect of rotor geometry on the performance of Wells turbine, Proceedings of the 13th International Offshore and Polar Engineering Conference, International Society of Offshore and Polar Engineers, Honolulu, Hawaii, USA, 1, 374–381.Google Scholar