Abstract
An Uncertainty Quantification analysis of a swirled stabilized combustor experiment is performed. Theobjective is to estimate the modal risk factor of the system, i.e. the probability of a thermoacoustic mode tobe unstable, which may facilitate the development and optimization of suitable control methods. Topropagate uncertainties, a Monte Carlo method is initially used based on 4000 Helmholtz-basedthermoacoustic simulations with random perturbations on the flame input parameters. The analysis of theMonte Carlo database suggests that a reduced two-step Uncertainty Quantification strategy may beefficient to deal with thermoacoustic systems. First, three bilinear surrogate models are tuned from amoderate number of Helmholtz solutions (a few tens). Then, these algebraic models are used to perform aMonte Carlo analysis at reduced cost and approximate the risk factor of the mode. Good agreements areobtained when comparing the risk factor from the full Monte Carlo database and the risk factor fromsurrogate models.