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Coaxial Horizontal Axis Hydrokinetic Turbine System: Numerical Modeling and Performance Optimization
Journal of Renewable and Sustainable Energy
  • A. Abutunis
  • M. Fal
  • O. Fashanu
  • K. Chandrashekhara, Missouri University of Science and Technology
  • L. Duan

Hydrokinetic turbines extract energy from free-flowing water, such as river streams and marine currents. For river applications, the typical deployment location is highly space-constrained due to both the nature of the river (i.e., its natural width and depth) and the other usages of the river. Therefore, a modified design of a conversion device is desired to accommodate these space limitations. The objective of this work is to derive optimum design criteria for a coaxial horizontal axis hydrokinetic turbine system utilizing both numerical and experimental approaches. Single-turbine systems configured with different sizes of untwisted untapered blades were numerically studied to obtain the optimum solidity and to examine the blockage effects on the various-solidity rotors. The numerical modeling was, then, extended to analyze the performance of the coaxial multi-turbine system (equipped with optimum-solidity rotors) and characterize its ambient flow. The numerically predicted power outputs were validated against those measured with torque and rotational speed sensors in a water tunnel for both single-turbine and multi-turbine systems. Particle image velocimetry was also utilized to evaluate the wake structure and validate the numerical results of the flow characteristics. The optimum-solidity for the single-turbine system was found to be 0.222 48. An optimum-solidity three-turbine axial system can increase power output by 47% when compared to an optimum-solidity single-turbine system. Increasing the number of rotors from three to five only enhanced efficiency by about 4%. The study of wake structures behind a three-turbine system showed that the highest velocity deficit occurs behind the second rotor rather than the third rotor.

Mechanical and Aerospace Engineering
Research Center/Lab(s)
Center for High Performance Computing Research
Second Research Center/Lab
Intelligent Systems Center
Document Type
Article - Journal
Document Version
File Type
© 2021 American Institute of Physics (AIP), All rights reserved.
Publication Date
Publication Date
01 Mar 2021
Citation Information
A. Abutunis, M. Fal, O. Fashanu, K. Chandrashekhara, et al.. "Coaxial Horizontal Axis Hydrokinetic Turbine System: Numerical Modeling and Performance Optimization" Journal of Renewable and Sustainable Energy Vol. 13 Iss. 2 (2021) ISSN: 1941-7012
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