ECN developed the code ECNS (Energy-Conserving Navier-Stokes solver), an incompressible code specifically suited for computing unsteady turbulent wakes in offshore wind farms.
The purpose of ECNS is to increase the understanding of the flow physics of these wakes. This increased understanding enables ECN to give better advice on wind farm designs. Furthermore, the increased understanding of the flow physics enables further improvement of ECN’s engineering model FarmFlow. FarmFlow is ECN’s tool for designing efficient wind farms, as well as for operating existing wind farms in a more efficient way: with the power production of the wind farm balancing well with the undesired fatigue loads experienced by each wind turbine. At present, FarmFlow has been used successfully for the evaluation of annual yield of several wind farm designs, both onshore and offshore.
ECN has its own wind turbine test location in Wieringermeer with various turbines for experimental research and a scaled wind farm. Experiments on wake aerodynamics are performed that were used for the validation of FarmFlow. The results of ECNS will now be added to further improve FarmFlow, in order to service the wind industry with streamlined solutions.
The code ECNS has been developed by Benjamin Sanderse. He defended his PhD. work on ECNS successfully at the Eindhoven University of Technology on 19 March 2013, and he even received the distinction cum laude. In order to get accurate results, he worked on a new methodology of solving aerodynamics equations by applying an energy conserving finite volume discretization method. Mr. Sanderse performed this work for ECN in close co-operation with CWI, the national research institute for mathematics and computer science in the Netherlands.
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Press release, March 21, 2013; Image: ecn