Numerical analyses of a high pressure sooting flame with multiphysics approach

The development of a new standard for soot emissions proposed by ICAO-CAEP to reduce the environmental impact of civil aviation is moving increasingly research effort on the investigation of sooting flames. Formation and oxidation of the particulate matter are strongly affected by gas temperature, requiring an accurate prediction of the flow field from a numerical point of view. On the other hand, the temperature distribution within the combustor is modified by radiation, which depends on the soot concentration, leading to a very challenging coupled problem. In this work, a series of sensitivity analyses in RANS context are performed on soot, radiation and heat transfer modelling to assess their impact on the prediction of soot emission, gas temperature as well as wall heat fluxes distribution in the context of a high pressure sooting flame which is representative of a RQL combustor. These results are employed to set up a CHT (Conjugate Heat Transfer) simulation, using the multiphysics THERM3D procedure in a loosely-coupled manner where reactive CFD, radiation and heat conduction calculations are computed sequentially with a separate solver in a dedicated framework. These sensitivities can provide useful information for the numerical setup in high-fidelity simulations, as Scale Resolving Simulations.