The goal of this WP is to analyse, with Large Eddy Simulation, the complex coupling between an RDE chamber and an ejector. The complete system injector – Combustion chamber – Ejector will be simulated for the first time in a high-fidelity fully coupled LES of RDE using the MISCOG technique (Wang et al 2014). This will allow a well-posed efficiency analysis of an RDE design and a precise measure of the gap between the actual efficiency of RDEs and their theoretical idealized counterpart (Fickett-Jacobs cycle). The project will also focus on the impact of the ejector design (and other systems) on the effective efficiency of the RDE. These results will be of great fundamental and practical value for the RDE community.