Computationally Efficient, Accurate and Uncertainty Characterized Chemical Kinetics for Hydrocarbon Fuels

High-pressure turbulent combustion occurs in many combustion devices critical to the Air Force. Notwithstanding significant progress in computational modeling of these devices; several challenges have remained. A fundamental challenge is identification of reaction pathways and reactions in small molecule foundational chemical kinetics requiring improvements under these high-pressure turbulent conditions. During Phase I, this team performed first known sensitivity calculations of the HyChem model at a high-pressure turbulent condition. These analyses were enabled by two-dimensional DNS calculations at high Karlovitz number and high-pressure that identified several reactions showing higher sensitivity to high-pressure turbulent conditions. The team also identified Perfectly Stirred Reactor Network based approach as a reduced-dimensional computational framework to emulate the sensitivities of chemical kinetics under high turbulence. During the Phase II, this framework will be developed for a wider range of high turbulence conditions utilizing limited number of three-dimensional DNS calculations. Sensitivity analyses of the foundational chemistry model will be performed with this framework under a wider range of relevant conditions. Recommendations from these analyses will lead to a limited number of high-pressure shock tube experiments and ab-initio calculations to improve reaction rate constants. Significant efforts will be made to integrate these tools into Air Force workflow.