This thesis investigates the modeling and analysis of non-premixed Rotating Detonation Engines (RDE) using the commercial CFD software ANSYS Fluent. While the main focus was given to the numerical ignition strategies for initiating combustion reactions through the high-speed diffusing fuel-oxidizer mixture within the annular rotating detonation combustor, an extensive study of effective meshing and accurate high-fidelity 3D reactive URANS simulation methodologies was also pursued. The manuscript is organized into several integral sections, commencing with an introduction to detonation physics, followed by an exploration of RDE thermodynamics and the fundamental equations governing fluid dynamics and combustion processes. A comprehensive review of the current state of the art in RDE simulations is presented.