Flames/Acoustics coupling in Swirling spray Multi-Injection Chambers – FASMIC

It is well known that clean combustion technologies considered for future propulsion applications are often impaired by combustion instabilities. These combustion-driven oscillations need to be taken into account at the design stage level to minimize their impact on the engine-operating domain. These dynamical phenomena raise difficult scientific and technological challenges. The project FASMIC addresses three of these challenges that are not well documented and nevertheless quite central: (1) The description of the dynamics of liquid fuelled injectors and air swirling flames; (2) The coupling between the two-phase flow and flame dynamics, and acoustics; and (3) The collective response of multiple-injector configurations to longitudinal and azimuthal modes. To improve design tools for stability prediction, these three issues need to be addressed simultaneously and are all considered in the present project. The response of liquid fuelled swirling flames in three complementary configurations equipped with the same fuel injectors to longitudinal and/or transverse acoustic forcing is investigated experimentally and numerically at CORIA (UMR CNRS), EM2C (UPR CNRS) and CERFACS laboratories. These data will be used by the three partners to develop models and simulations to predict the stability of the chambers and to validate predictions by comparison with experiments. In addition, analysis of the basic mechanisms and developments of the associated methodologies will have spin-offs in a much wider domain than just that of academic configurations, as they will provide the necessary knowledge and tools allowing to design advanced combustor architectures that could reach the ambitious goals set in terms of reduction in fuel consumption and in pollutant emission levels to face increasingly severe societal requirements as well as environmental regulations in a context of continuous growth of worldwide air traffic. The acquired knowledge will be useful to the design of novel clean aeronautical propulsion systems by providing state-of-the-art models. This should participate in the enhancement of competitiveness of the aeronautical industry in world transport markets.