Simulation and Optimization of a Double-Helical Rotor Wave Energy Converter

Abstract

This paper presents a new type of double-helical rotor wave energy converter (WEC), which consists of two isolated sets of helical rotor structures (inner and outer). This device can generate electricity by using the rising and falling energy of a wave. The rotors are simulated and optimized by Fluent. Each rotor’s blades are simulated and analyzed, which are separately changed in terms of helix angle, shape, and thickness. The simulation result shows that, for both inner and outer helical rotors, the energy harvesting efficiency is the highest when the blade helix angle is 45°. Triangular blades have better hydrodynamic performance than square and circular blades. The energy harvesting efficiency of 15 mm thick blades is higher than that of 75 mm thick blades.

Keywords

Sustainable energy / Wave energy / Double-helical rotor WEC / Structural optimization / Numerical simulation

References

[1] Ansys (2011) Ansys Fluent theory guide, Release 14.0. Ansys Inc Canonsburg, USA, 40–46

[2] Al-Habaibeh A, Su D, McCague J, Knight A. An innovative approach for energy generation from waves. Energy Convers Manage, 2010, 51(8): 664-1668

[3] Beatty SJ, Hall M, Buckham BJ, Wild P, Bocking B. Experimental and numerical comparisons of self-reacting point absorber wave energy converters in regular waves. Ocean Engineering, 2015, 104: 370-386

[4] Cheng N, Chen C. Research on the double effects of marine carbon sinks based on the “double carbon” goals. Journal of Shandong University (Philosophy and Social Sciences), 2021, 2021(6): 150-161

[5] Chen H (2014) A double helical rotor type marine energy conversion system. CN Patent 103511162 A

[6] Cong D, Shang J, Luo Z, Sun C, Wu W. Energy efficiency analysis of multi-type floating bodies for a novel heaving point absorber with application to low-power unmanned ocean device. Energies, 2018, 11(12): 3282

[7] Cui Y, Liu Z, Zhang X, Xu C. Review of CFD studies on axial-flow self-rectifying turbines for OWC wave energy conversion. Ocean Engineering, 2019, 175: 80-102

[8] Dean RG. Water wave mechanics for engineers and scientists. Advanced Series on Ocean Engineering, 1984, 2: 353

[9] Edenhofer O, Madruga RP, Sokona Y. Renewable energy sources and climate change mitigation: special report of the intergovernmental panel on climate change, 2011, Cambridge, United Kingdom: Cambridge University Press

[10] Hinze JO. Turbulence, 1975, New York: McGraw-Hill Publishing Co, 61-62

[11] Kaneko K, Setoguchi T, Raghunathan S (1991) Self-rectifying turbines for wave energy conversion. The First International Offshore and Polar Engineering Conference, Edinburgh, 385–392

[12] Lenee-Bluhm P, Paasch R, Oezkan-Haller HT. Characterizing the wave energy resource of the US pacific northwest. Renewable Energy, 2011, 36(8): 2106-2119

[13] Liao WJ, Wang YS. The development of wave power generation technology in the world. The Magazine on Equipment Machinery, 2010, 2: 68-73 (in Chinese)

[14] Li JY (2015) Numerical simulation and experimental study of double helical rotors type wave energy converter. PhD thesis, Jimei University. (in Chinese)

[15] Li Y, Yu YH. A synthesis of numerical methods for modeling wave energy converter-point absorbers. Renewable & Sustainable Energy Reviews, 2012, 16(6): 4352-4364

[16] Liu B. Fluent 19.0 fluid dynamics simulation from beginner to master, 2019, Beijing: Tsinghua University Press, (in Chinese)

[17] Liu B, Levi C, Estefen SF, Wu Z, Duan M. Evaluation of the double snap-through mechanism on the wave energy converter’s performance. Journal of Marine Science and Application, 2021, 20(2): 268-283

[18] Liu SM, He HZ, Li JY. Numerical simulation analysis on the double helix rotor type wave energy power generation device. Ocean Technology, 2017, 36(2): 111-115 (in Chinese)

[19] Patankar SV, Spalding DB (1983) A calculation procedure for heat, mass and momentum transfer in three-dimensional parabolic flows. Numerical prediction of flow, heat transfer, turbulence and combustion. Pergamon Press, 54–73

[20] Reguero BG, Losada IJ, Méndez FJ. A recent increase in global wave power as a consequence of oceanic warming. Nat Commun, 2019, 10: 1-14

[21] Reynolds O (1995) On the dynamical theory of incompressible viscous fluids and the determination of the criterion. Proceedings of the Royal Society-Mathematical and Physical Sciences, London, 535–577

[22] Ružinski N, Jebaraj S, Iniyan S, Suganthi L, Goić R. An optimal electricity allocation model for the effective utilisation of energy sources in India with focus on biofuels. Management of Environmental Quality: An International Journal, 2008, 19(4): 480-486

[23] Shehata AS, Saqr KM, Xiao Q, Shehadeh MF, Day A. Performance analysis of wells turbine blades using the entropy generation minimization method. Renewable Energy, 2016, 86: 1123-1133

[24] Shehata AS, Xiao Q, Saqr KM, Naguib A, Alexander D. Passive flow control for aerodynamic performance enhancement of airfoil with its application in Wells turbine—Under oscillating flow condition. Ocean Engineering, 2017, 136: 31-53

[25] Sun C, Luo Z, Shang J, Lu Z, Zhu Y, Wu G. Design and numerical analysis of a novel counter-rotating self-adaptable wave energy converter based on CFD technology. Energies, 2018, 11(4): 694

[26] Tan SM, Qing HH, Zhao X. International patent analysis for ocean wave energy. Journal of Modern Information, 2011, 31(9): 14-17 (in Chinese)

[27] Wang H, Li Y, Pröbsting S, Zheng X, Hu Q, Chen D, Liu H, Wu X. Aerodynamics of the Wells turbine with a Hawkmoth-inspired blade design. Bioinspiration & Biomimetics, 2020, 15(6): 066001

[28] Xiao H, Liu Z, Zhang R, Kelham A, Xu X, Wang X. Study of a novel rotational speed amplified dual turbine wheel wave energy converter. Applied Energy, 2021, 301(1): 117423

[29] Yang Y, Dia I, Morales M. A vertical-axis unidirectional rotor for wave energy conversion. Ocean Engineering, 2018, 160: 224-230