Determination of heat release response function from 2D hybrid RANS-LES data for the CVRC combustor

Combustion instability phenomenon arises from the coupling between heat release and acoustics. Several studies have been carried out in the past years with very different tools, from analytical studies to high fidelity simulations, like large eddy simulations (LES) or hybrid RANS-LES simulations. Despite the promising results, the computational effort required for such detailed numerical tools can be prohibitive for many applications. For this reason simplified models represent an alternative approach that needs to be improved. The main difference between the simplified approaches with respect to detailed simulations is the necessity, for the former, of the preliminary knowledge of response functions, describing the coupling between heat release and acoustics. Looking for response function suitable to model longitudinal combustion instabilities in one-dimensional formulations, three different approaches are presented to extract them from hybrid RANS-LES simulations data.