Actuator line method applied to grid turbulence generation for large-Eddy simulations

Abstract

The constant growth of computational resources allows performing Large-Eddy Simulation (LES) on realistic flow configurations. In this context, it is important to properly model boundary conditions and particularly inflow turbulence. This study addresses wind tunnel applications where the object under investigation is downstream of a turbulence grid. This grid aims at generating a highly turbulent sheared flow for further use in wind turbines applications. In this work, an original strategy based on the actuator line method (ALM) is proposed to emulate the grid and generate realistic flow structures downstream at a moderate computational cost. As a first validation test of the proposed method, the LES of a single square rod is performed and the results are compared to a scale resolving simulation. In a second phase, the method is applied to a passive grid with non-homogeneous spacing, which generates fully-developed turbulence. Results are compared to experimental data and other state-of-the-art turbulence injection strategies such as homogeneous isotropic turbulence injection and also scale resolving simulations.

Keywords:

• LES
• actuator line method
• grid turbulence

Acknowledgments

This work was granted access to the HPC resources from CRIANN (Centre Régional Informatique et d'Applications Numériques de Normandie) under the allocation 2012006 and from TGCC-CEA under the allocations x20172b6880 made by GENCI (Grand Equipement National de Calcul Intensif). This project was co-financed by the European Union with the European regional development fund (ERDF, HN0005592) and by the Normandy Regional Council via the NEPTUNE project. Part of this work was funded by the Fonds de la Recherche Scientifique de Belgique (F.R.S.-FNRS, Mobility grant for Insa-Rouen).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This project was co-financed by the European Union with the European Regional Development Fund (ERDF, HN0005592) and by the Normandy Regional Council via the NEPTUNE project. Part of this work was funded by the Fonds De La Recherche Scientifique de Belgique (F.R.S.-FNRS, Mobility grant for Insa-Rouen).