The Jet Erosion Test (JET) is an experimental device increasingly used to quantify the resistance of soils to erosion. This resistance is characterised by two geotechnical parameters: the critical shear stress and the erosion coefficient. The JET interpretation model of Hanson and Cook (2004) provides an estimation of these erosion parameters. But Hanson's model is simplified, semi-empirical and several assumed hypotheses can be discussed. Our aim is to determine the relevance of the JET interpretation model. Therefore, we developed a numerical model able to predict the erosion of a cohesive soil by a turbulent flow. Our numerical model is first validated on a benchmark: erosion of an erodible pipe by a laminar flow. The numerical results are satisfactorily compared with the theoretical solution. Then, three JETs are modelled numerically, with values of erosion parameters obtained experimentally. A parametric study is also conducted to validate the accuracy of the numerical results and a good agreement is observed. The erosion parameters found experimentally permit to predict numerically the evolution of the erosion pattern within good accuracy. This result contributes to the validation of the JET's semi-empirical model. The numerical model also gives a complete description of the flow, including vortices which can be observed in the cavity created by erosion. The whole erosion pattern evolution is given by the numerical results. Our numerical model gives information that is not available otherwise.