This project has the aim characterising the friction between a plate and a fluid, in this case sea water. The analysis has been done with different geometries: with a flat plate and with a plate with small perturbations. The objective come from the necessity of studying and reducing the friction in ships to decrease emissions and fuel consumption. To characterise the friction between a plate and a fluid it has been used the software COMSOL Multyphisics. Different meshes and turbulent models have been used to observe the differences between them and contrast the obtained results with experimental data. After analysing different mesh configurations and different models for turbulent flow it has been proved that the results are strongly related to the used mesh, and in lower manner to the used method. The key element to obtain results practically equal to the obtained in the experimental test has been the mesh in the boundary layer. There has been considered different parameters from the mesh to evaluate its quality. It has also been checked that an analysis in two-dimensions, for the used geometry, is enough for computing the friction that would suppose the body in three-dimensions. This has given the possibility to work with a large quantity of meshes due to the model in 3D requires an important computing power.