(46g) A Framework for Chemical Kinetics Extraction Based on Reactive Molecular Dynamics

Understanding the thermo-chemical response of materials is a key aspect of material design in several applications which involve processes like pyrolysis, ablation, catalysis and combustion. There is a need to gain a fundamental understanding of the phenomena and develop predictive models which are capable of capturing the chemical kinetics and thermo-chemical response of materials in such high temperature and pressure environments.

In this presentation, we discuss a computational framework and pertinent tools which have been developed to investigate material degradation behavior and chemical kinetics in aforementioned scenarios. The framework makes use of reactive molecular dynamics (RMD) simulations and a host of custom tools developed to enable extraction of reaction chemistry – both chemical pathways and chemical kinetics. These tools christened as MolfrACT^TM (Molecular Fraction Analysis Custom Toolkit) and KinACT^TM (Kinetic Analysis Custom Toolkit) together provide a general-purpose menu-based command mode tools that enable automated extraction of chemical reactions and their kinetics. Further, we discuss recent developments with Accelerated Reactive Molecular Dynamics Simulation (ARMS) framework for investigating low temperature degradation phenomena. We discuss the development of these tools and their applicability to extract reaction chemistry without any a-priori assumption on the reaction behavior, for surrogate polymeric ablators which are undergoing pyrolysis. The resulting framework provides an atomistically-based computational chemistry approach to gain fundamental insights on degradation processes as well as enables extraction of chemical kinetics data.

Acknowledgements: The work presented in this talk, has been supported by different SBIR/STTR programs funded by NASA and NAVAIR-U.S. Navy. The simulations under this project were undertaken using high-performance computing infrastructure of NSF Extreme Science and Engineering Discovery Environment (XSEDE) under allocation TG-SBR150001 of Dr. Srujan Rokkam.