Sliding mesh simulations of a wind turbine rotor with actuator line lattice-Boltzmann method

Simulating entire wind farms with an actuator line model requires significant computational effort, especially if one is interested in wake dynamics and wants to resolve the tip vortices. A need to explore unconventional approaches for this kind of simulation emerges. In this work, the actuator line method is implemented within a lattice-Boltzmann flow solver, combined with a sliding mesh approach. Lattice-Boltzmann solvers have advantages in terms of performance and low dissipation, while the sliding mesh allows for local refinement of the blade and tip vortices. This methodology is validated on a well-documented case, the NREL Phase VI rotor, and the local refinement is demonstrated on the NREL 5 MW rotor. Results show good agreement with reference Navier-Stokes simulations. Advantages and limitations of the sliding mesh approach are identified.