A coupled DES - Actuator Lines Model to represent the interaction between tidal flows and Marine Hydrokinetic Turbines

Marine hydrokinetic (MHK) devices have an important influence on the surrounding environment in many key aspects, i.e. local flow conditions, sediment transport, ecosystem dynamics, submarine noise, among others. Furthermore, wake interactions among devices in turbine arrays play a significant role in energy extraction performance. To study the complex phenomena associated to these processes and their implications, numerical simulations are a necessary tool to assess the dynamics of the flow, providing detailed information and supporting a wide range of application cases.

This study presents a coupled detached-eddy simulation (DES) model for the flow with an Actuator Lines Model (ALM) for the turbine blades. The advantage of coupling these models is the combination of two relevant features: (1) a detailed representation of the turbulent flow through a resolved coherent dynamics approach; (2) the rotational effects of turbine blades on the local hydrodynamics incorporated as a body force on the flow. This combined scheme can be carried out with relatively low computational costs, and allows to study both the axial and helicoidal vortical structures and their interaction processes for different turbines arrays. In this work, we contribute to further the understanding of the hydrodynamic behavior of MHK devices, and give insights about the effects that they will have on their environment, with emphasis in ambient turbulence, flow characteristics, and energy extraction performance.

Work supported by Chile's Marine Energy Research & Innovation Center (MERIC) CORFO project 14CEI2-28228. Powered@NLHPC: This research was partially supported by the supercomputing infrastructure of the NLHPC (ECM-02)