The Freeman-FT4 powder rheometer is a universal tool to study powder properties. It is widley used for pharmaceutical purposes, also by the Swiss company Novartis. This thesis concerns the numerical study of the rheometer. The Discrete Element Method is used, because it is particularly indicated to treat granular materials. This method is implemented in a code called GFX, written in Fortran90 by Dr. Mark Sawley from EPFL. Several simulations are done and compared to the experimental results fournished by Novartis. Both a qualitative and quantitative post-processing is done to analyze the results obtained. A part of the work is also dedicated to the visualization done with ParaView.