This article aims at introducing the first steps of development and validation of a CFD tool dedicated to realistic tidal turbine farm modelling. The fluid solver is presented in details, together with the actuator disc model used to represent tidal turbines. A particular attention is paid to the spatial scheme in order to limit the numerical diffusion in the wakes. Comparisons with experimental results from Mycek et al. [1] on a horizontal axis tidal turbine (HATT) are presented and discussed. For the different cases, averaged axial velocities and averaged turbulence intensity rates are compared from 1.2 to 10 tidal turbine diameters behind the device. The properties of this tool are discussed in terms of accuracy, CPU costs and applicability to industrial purpose. (C) 2017 Elsevier Ltd. All rights reserved.