Cross flow water turbines: HARVEST technology

This paper describes all the main features of the hydrokinetic devices developed during the HARVEST program. Such devices, which eliminate the well-known weaknesses of Darrieus turbines, are composed of two counter-rotating twin columns of cross flow water turbines (CFWT) built in a support structure with a twin towers shape. Among other advantages, it is shown that the twin towers geometry facilitates the optimal design of arrays of HARVEST Power Systems. In particular simple 2D models can be used in a first approach to predict power extraction of single-row arrays. Blade Element Momentum–Reynolds-Averaged Navier-Stokes Simulations (BEM-RANS) models are currently developed to yield a fast and accurate prediction of the power output produced by a row of many power systems. Relevant momentum source terms describing the rotor effects, which are required by this simplified modelling, are defined beforehand from a set of high-fidelity Unsteady Averaged Navier-Stokes Simulations (URANS) simulations for an isolated HARVEST Power System