The objective of this document is to present the architecture of the global model that is developed within the LiftWEC project to provide efficient simulation of the LiftWEC concepts. The global model provides a tool with coupled analysis of the rotor and support structure dynamic, and will be able to integrate advanced control strategies.

While the global model does not focuses on the precise hydrodynamic modelling of any elements of the LiftWEC concepts, it aims at providing an efficient and accurate enough modelling tool to provide inputs for design for the other work packages (physical modelling, structure, O&M, LCoE) and to support the assessment of the concepts.

From the tehnical specifications layed out in this document, the general architecture of the future global model is presented as a modular system. The data flow between the enviornment and the several computational module are explicited:

The support structure module will be based on linear potential flow hydrodynamics and the rotor module will implement a approach based on tabulated lift and drag coeficients of the foils. The flow velocity estimation at the hydrofoil levels considers the incident potential floaw and the radiated and difracted flow from the support structure.

A demonstrator model is presented. The comercial software Orcaflex is used to implement the support structure and the interaction with the rotor. A simple fixed speed control is considered. The rotor module is implemented by a external function that will form the core of the future rotor module. Lift and drag table coeficient are provided by LiftWEC partners.

The demonstrator module is used to simulate a possible LiftWEC configuration based on a slack-moored support structure and a 2 fixed pitch hydrofoils rotor. The results provided present the type of outputs that will be available from the future global model, i.e time series of speeds, rotor torque and trust, hydrofoils pahse angle and angle of attack of the foils among others.