The integration of Ultra High Bypass Ratio (UHBR) engines introduces important restrictions of space for the aircraft pylon, and as a consequence on the embedded bleed air system. Under this scenario, a reduction of the size of pre-coolers is demanded, and the selected option by Clean Sky 2 program is to achieve this goal by the introduction of air-air ejectors. Therefore, the current research is mainly aimed at gaining knowledge on supersonic ejectors for aeronautical applications, and to reproduce their behaviour by means of simplified models. For this purpose, a combined methodology based on experimental and CFD analyses is proposed to obtain physical insights and validation material for the development of a robust and accurate lumped model, capable of simulating the dynamic ejector behaviour in normal and abnormal conditions. In this paper, an overview on the performed activities is provided.