A hybrid real/ideal gas mixture model in the framework of low order modeling of combustion instability

The present work focuses on the verification and validation of new mathematical and numerical tools which have been specifically developed to face combustion instability problems, using a low-order approach. In the low-order framework, flow field is computed using an Eulerian set of equations for three species, namely oxidizer, fuel and combustion products mixtures. A simplified real fluid equation of state is adopted, capable of handling a hybrid mixture of ideal and real fluids, so that the cooler oxidizer can be described as a real fluid, while hotter species can be approximated as ideal gases, in order to simplify computations. Mentioned models are embedded into an in-house solver. Verification and validation of the new code against wave propagation problems are then performed, showing good agreement.