This article presents the procedure followed to simulate the airow in a HOLSET HT3B centrifugal compressor using FLUENT e and GAMBIT e , both CFD (Computer Fluid Dynamics) packages, which are based on thenite volume technique. Initially some important considerations will be presented, which must be considered when using the CFD tools for theow simulation; later, the simulation process will be described to obtain therst results, and their most relevant characteristics will be discussed briey. It is important to mention that this article makes reference to the initial simulation of theow in the mentioned compressor, and that some recommendations for the operational parameters adjustments are presented as a plus.