ECNS: a new dedicated Navier-Stokes code for wind-turbine wake simulations

Abstract. In this article we describe a new Energy-Conserving Navier-Stokes code (ECNS) for the simulation of incompressible turbulent flow in wind-turbine wakes. The discretization in space and time is energy conserving, which results in two important properties: (i) the discretization does not introduce numerical viscosity and (ii) the discretization is stable for any mesh and any time step. A new class of non-diffusive actuator methods is used to simulate the effect of the wind turbine on the flow. The non-diffusive properties of the code are illustrated with the roll-up of a tip vortex and the flow through an actuator disk.