Heat pipes are widely used in satellite thermal control systems to transport heat from heat-generating components to the cooler parts of the satellite. Computational Fluid Dynamics (CFD) is widely used in the design and optimization of those components. In the open literature, however, little material is present regarding high-fidelity simulations that can describe both the fluid behaviour inside the grooves and the overall thermal performance. Moreover, information about the fluid behaviour inside the heat exchanger is not easy to obtain experimentally due to the difficulty of obtaining visual data inside the aluminium coating. This thesis aims to propose a computational model that is able to predict fluid behaviour in grooved heat pipes.