Recent trends in aeroengine developments aim at developing high thrust, low emission engines based on innovative concepts. Amongst them, the use of pressure gain combustion should ensure that cycle efficiency will raise by 17%, at least for low compression ratios (e.g., short-haul flights, helicopters). Such a remarkable increase entails a significative reduction in pollutant emissions, which reduces to net zero if hydrogen is considered as energy carrier (not considering NOx emissions). An interesting way to realize the Zeldovich-Neumann-Doring cycle includes the usage of a rotating detonation combustor. The resulting outflow of this unconventional machine is characterized by a high frequency fluctuation of temperature, flow angle and Mach number.