1. How Do We Control Material Processes at the Level of Electrons? Progress on Grand Challenge New Horizons for Grand Challenge Remaining ChallengeRefreshed Grand Challenge? Control of combustion requires understanding how the electronic structure of the fuel affects the progression of chemical kinetics in various states of burning. Predicted thermochemical and kinetics properties of key combustion species and developed new methods to treat complex reaction pathways and networks. Design fuels with fundamentally new structures and properties through manipulation of the molecular structure at the level of electrons. Is a new statement of the Grand Challenge needed? No Should the Grand Challenge be retired? No Submitted by: Lilian Tsang Affiliation: Princeton University

2. How do we design and perfect atom- and energy-efficient synthesis of revolutionary new forms of matter with tailored properties? Progress on Grand Challenge New Horizons for Grand Challenge Remaining ChallengeRefreshed Grand Challenge? Design of successful fuels with fundamentally new structures and properties requires a multi-scale understanding of how their tailored atomic structure leads to the desired emergent properties. Tested and analyzed candidate biofuels, especially bio-alcohols and biodiesels, and acquired guidance on fuel molecular and compositional design for optimum combustion performance. Develop a multi-scale approach to characterize and tailor the properties of matter at atomic scales in terms of evolving properties at the mesoscale and beyond. Is a new statement of the Grand Challenge needed? No Should the Grand Challenge be retired? No

3. How do we characterize and control matter away - especially very far away - from equilibrium? Progress on Grand Challenge New Horizons for Grand Challenge Remaining ChallengeRefreshed Grand Challenge? Understand and control reactions of fuels in situations very far from equilibrium and under extreme conditions of low temperatures and high pressures to produce cleaner and more efficient energy delivery using advanced devices. Developed and validated regime- independent turbulence-chemistry sub- models from coordinated DNS simulations and experiments on configurations that isolate near-limit combustion at conditions far from equilibrium. Chemical kinetics and turbulent flow dynamics in extreme combustion environments require the application of nonequilibrium theories. Is a new statement of the Grand Challenge needed? No Should the Grand Challenge be retired? No