Abstract

As concerns about rising fossil-fuel prices, energy security and climate-change increase, renewable energy plays a vital role in producing local, clean and inexhaustible energy to supply world rising demand for electricity. In this study, hydrodynamic analysis of vertical axis tidal turbine (both fixed pitch and variable pitch) is numerically analyzed. Two-dimensional numerical modeling and simulation of the unsteady flow through the blades of the turbine is performed using ANSYS CFX, hereafter CFX, which is based on a Reynolds-Averaged Navies-Stokes (RANS) model. A transient simulation is done for fixed pitch and variable pitch vertical axis tidal turbine using a Shear Stress Transport turbulence (SST) scheme. Main hydrodynamic parameters like torque T, combined moment C_M, coefficients of performance C_P and coefficient of torque C_T, etc., are investigated. The modeling and meshing of turbine rotor is performed in ICEM-CFD. Moreover, the difference in meshing scheme between fixed pitch and variable pitch is also mentioned. Mesh motion option is employed for variable pitch turbine. This study is the one part of the ongoing research on turbine design and developments. The numerical simulation results are validated with analytical results performed by Edinburgh design Ltd. The study concludes with a parametric study of turbine performance, comparison between fixed pitch and variable pitch operation for a four-bladed turbine. It is found that for variable pitch we get maximum CP and peak power at smaller revolution per minute N and tip sped ratio λ.

Keywords:

Fixed and variable pitch, simulation, tidal current device, tidal current turbine CFD, tidal energy, Vertical Axis Tidal Turbine (VATT),

References

Competing interests

The authors have no competing interests.

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Copyright

The authors have no competing interests.