New Combustion Concepts to Enhance the Thermodynamic Efficiency of Propulsion Engines

The reduction of fuel consumption in future propulsive engines is an ambitious target that will be reached only with a technological breakthrough. Two of the possible solutions are being investigated experimentally and numerically by MBDA France, ONERA, PPRIME and SAFRAN Tech. Changing the actual thermodynamical cycle through the use of Constant-Volume Combustion or Rotative Detonation concepts could theoretically enable this target to be reached. Implementing such concepts requires a deep knowledge and control of several basic phenomena that will occur and interact in real engines, such as: mixing processes, ignition, flow effects, dilution by residual burnt gas, etc.
This article presents recent studies carried out on these elementary processes that must be considered in high-velocity flows and under non-stationary conditions, whatever the concept (CVC or RDE). The results provide a comprehensive insight into constant-volume combustion and detonation dynamics from simulation and experiments on a reduced scale or full scale prototype, which enables the physical phenomena to be understood and modeled, and the potential of such concepts for future propulsion to be highlighted.