Uncertainty Analysis of the Modified Marrone–Treanor Model

This work presents an uncertainty and sensitivity analysis of the Modified Marrone–Treanor (MMT) model to evaluate the impact of uncertainties in quasiclassical trajectory (QCT) collision data-derived parameters. Two zero-dimensional reactor simulation cases were analyzed for preliminary sensitivity analysis, followed by two-dimensional hypersonic cylinder flow CFD simulations. Surrogate models enabled variance-based sensitivity analysis using Sobol indices to identify which reaction parameters most significantly impact the CFD outputs. Two cases were analyzed: one representative of shock tunnel experimental conditions and one of flight conditions. Results reveal that under experimental conditions, only the pre-exponential factors influence the solution, with negligible sensitivity to MMT-specific parameters. In contrast, flight conditions show substantial influence from the MMT parameters, suggesting that current shock tunnel experiments may not adequately constrain the parameters most relevant to flight prediction.