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Active Subspace Variation and Modeling Uncertainty in a Supersonic Flame Simulation

2021; American Institute of Aeronautics and Astronautics; Volume: 59; Issue: 5 Linguagem: Inglês

10.2514/1.j059977

1533-385X

Nana Wang, Tianwei Yang, Zhuyin Ren,

Probabilistic and Robust Engineering Design

The active subspace method is applied to Burrows–Kurkov supersonic wall-jet flame to quantify modeling uncertainties associated with chemical kinetics, turbulence combustion models, and boundary conditions, as well as to investigate the evolution of key physiochemical process throughout the supersonic flame. One-dimensional active subspaces of the uncertain parameter space are identified for both flame liftoff length and flame–wall distance. Through the analyses of active subspaces, it shows that chemical kinetics plays a dominant role for flame initialization and early development, whereas turbulent transport becomes more important as the flame develops. The univariate response surfaces constructed in the active subspaces are then used to perform uncertainty quantification. For the flame liftoff length, the uncertainty introduced by chemical kinetics is slightly larger than that introduced by turbulence combustion models and significantly larger than boundary induced uncertainty; whereas the uncertainty in the predicted flame–wall distance is dominated by turbulence combustion modeling, and the contribution from boundary and chemical kinetics is trivial. Further comparison between two turbulence models with structural compressibility correction shows that the active subspace is insensitive to turbulence models at the same level of closure. The corrected shear stress tensor and corrected standard yield the same key physiochemical process and similar uncertainties in the predictions.