Unsteady wake modelling for tidal current turbines

Unsteady wake modelling for tidal current turbines

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The authors present a numerical model for three-dimensional unsteady wake calculations for tidal turbines. Since wakes are characterised by the shedding of a vortex sheet from the rotor blades, the model is based on the vorticity transport equations. A vortex sheet may be considered a jump contact discontinuity in tangential velocity with, in inviscid hydrodynamic terms, certain kinematic and dynamic conditions across the sheet. The kinematic condition is that the sheet is a stream surface with zero normal fluid velocity; the dynamic condition is that the pressure is equal on either side of the sheet. The dynamic condition is explicitly satisfied at the trailing edge only, via an approximation of the Kutta condition. The shed vorticity is the span-wise derivative of bound circulation, and the trailed vorticity is the time derivative of bound circulation, and is convected downstream from the rotors using a finite-volume solution of vorticity transport equations thus satisfying the kinematic conditions. Owing to an absence in the literature of pressure data for marine turbines, results from the code are presented for the NREL-UAE Phase IV turbine. Axial flow cases show a close match in pressure coefficients at various spanwise stations; however, yawed flow cases demonstrate the shortcomings of a modelling strategy lacking viscosity.


    1. 1)
    2. 2)
    3. 3)
      • H. Glauert . (1959) The elements of airfoil and airscrew theory.
    4. 4)
    5. 5)
      • Simms, D., Schreck, S., Hand, M., Fingersh, L.J.: `NREL unsteady aerodynamics experiment in the NASA-Ames Wind Tunnel: a comparison of predictions to measurements', Technical Report NREL/TP-500-29494, June 2001.
    6. 6)
    7. 7)
      • Leishman, J.G.: `Challenges in modeling the unsteady aerodynamics of wind turbines', Proc. 40th AIAA Aerospace Sciences Meeting and Exhibit Wind Energy Symp., January 2002, Reno, NV, p. 141–167.
    8. 8)
    9. 9)
    10. 10)
      • R.J. LeVeque . (2002) Finite volume methods for hyperbolic problems.
    11. 11)
    12. 12)
      • Sant, T., Kuik, G.V., Haans, W., Van Bussel, G.J.W.: `An approach for the verification and validation of rotor aerodynamics codes based on free-wake vortex methods', Proc. 31st European Rotorcraft Forum, 2005, Florence, Italy, 2005, p. 56.1–56.15..
    13. 13)
    14. 14)
    15. 15)
      • Maganga, F., Pinon, G., Germain, G., Rivoalen, E.: `Numerical simulation of the wake of marine current turbines with a particle method', Proc. Tenth World Renewable Energy Congress, June 2008, Glasgow, Scotland.
    16. 16)
      • Gharakhani, A., Stock, M.J.: `3d vortex simulation of flow over a circular disk at an angle of attack', Proc. 17th AIAA Computational Fluid Dynamics Conf., June 2005, Toronto, Ontario, Canada.
    17. 17)
    18. 18)
    19. 19)
      • Fletcher, T.M., Brown, R.E., Kim, D., Kwon, O.J.: `Predicting wind turbine blade loads using vorticity transport and rans methodologies', Proc. European Wind Energy Conf. Exhibition, March 2009, Parc Chanot, Marseille, France.
    20. 20)
    21. 21)
      • McCombes, T., Johnstone, C., Grant, A.: `Wake modelling for marine current turbines', Proc. Second Int. Conf. Ocean Energy, October 2008, Brest, France.
    22. 22)
      • Swarztrauber, P., Sweet, R.: `Efficient fortran subprograms for the solution of elliptic partial differential equations', Technical report, 1975.
    23. 23)
    24. 24)
    25. 25)
      • C. Hirsch . (1988) Numerical computation of internal and external flows.
    26. 26)
      • Godunov, S.K.: `Different methods for shock waves, Moscow State University', 1954, PhD, Moscow State University.
    27. 27)
    28. 28)
      • J. Katz , A. Plotkin . (2001) Low speed aerodynamics.
    29. 29)
    30. 30)
      • Baltazar, J., Falcão de Campos, J.A.C.: `Hydrodynamic analysis of a horizontal axis marine current turbine with a boundary element method', Proc. ASME 27th Int. Conf. Offshore Mechanics and Arctic Engineering, June 2008, Estoril, Portugal.

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