Scientific advances and innovation

Only 5 other codes have been identified as provinding a similar levels of precision and optimization as the one targeted by the Grid-flow/FAST coupling. Compared those tools, Grid-flow/FAST is designed to provide an important flexibility both in the simulation setup process and to follow the motion of simulated structures. This second feature gives a potential for the simulation of floating wind turbines, which could be the subject of a future project.

Expected technical and economic impact

The implementations planned within the ATMOSFARM project should allow the simulation of interactions between wind turbines at full scale. Grid-flow is distributed by NextFlow Software. The implementations realized during the ATMOSFARM project will be integrated to the software tools of NextFlow Software.

Key project milestones

  • June 2021 - ATMOSFARM project starts
  • Novembre 2021 - Numerical schemes optimized and validation on small scaled completed
  • Novembre 2021 - Atmospheric boundary layer at full scale simulated and demonstrator set


The ATMOSFARM project uses the coupling Grid-flow/FAST which was developped during the ECOSFARM project. This previous WEAMEC-funded project shows a proof of concept for the simulation of wake interactions between wind turbines.


December 2021

During the last 6 months, the developments have focused on the handling and optimization of the Gridflow/FAST coupling.

An in-progress calculation recovery facility has been set up, which is necessary for large-scale simulations

The simulations have been optimized at different points.

The post-processing devices have been parallelized.

Following these developments, a validation was carried out on small-scale academic cases. The BlindTest version 1 (Krogstad et al, 2013), 2 (Pierella et al, 2014) and 3 (Krogstad et al, 2015) cases, which provide experimental wind tunnel data, were used.


  • The results obtained with BlindTest 1 showed an interesting accuracy when moving away from the wind turbine. The results obtained in the near wake remain perturbed, due to the use of an Actuator Line method.


  • The results obtained with BlindTest 2 show a satisfactory accuracy. We also observe an improvement in the quality of the results compared to those obtained during the ATMOSFARM project. These differences can be explained by the improvement of the Gridflow resolution scheme,s as well as by the correction of bugs in the Gridflow/FAST coupling.


  • Preliminary results obtained in BlindTest 3 show significant deviations from the experimental results. Work is in progress to improve the consideration of interactions between wind turbines.


Comparisons have also been made to measure the influence of gradient reconstruction schemes.

The last point concerns the transition to a purely implicit temporal scheme. Preliminary work to adapt this scheme to the context of the Gridflow/FAST coupling is in progress.


The ability to simulate accurately an atmospheric boundary layer is the last obstacle before simulating wind turbine interactions at full scale. Further developments could allow the simulations of floating wind turbine.