Tim Kelley

The project will perform fundamental research in developing computational methods and tools for dynamic Monte Carlo (MC) neutron transport simulations on exascale class computer architectures. The NC State research team will perform studies on hybrid deterministic-MC and multi-level computational methods. The expected results of this research will form the background for development of efficient numerical methods and tools for time-dependent neutron transport problems and will be used to determine the next step in this direction. The results will be delivered as technical reports and papers published in technical journals and proceedings of major technical conferences. The project will educate two Ph.D. students

The PI will continue his research program in the design, implementation, analysis, and application of novel numerical methods for nonlinear equations and applications to multiphysics coupling, computational chemistry, and computational physics. The primary focus of the project is Anderson acceleration. This method is ubiquitous in quantum electronic structure codes. The PI will work on understanding CROP and CDIIS, two important variations of the method. The PI will also investigate open theoretical questions.

We plan to develop open-source software for quantum simulations of materials for future NSF supercomputing platforms.

The Consortium for Advanced Simulation of Light Water Reactors, CASL, supports the broad national missions of enabling energy independence; supporting economic growth through the offering of superior technology ; and being good stewards of the environment, buy enabling predictive simulation of nuclear power plants. Such capability will make possible power uprates, lifetime extension and higher fuel burnups for currently operating and new Generation III+ nuclear power plants.

The PI will continue his long-term collaboration with the US Army Engineer Research and Development Center (ERDC) on problems in inverse bathemetry. The objective is to determine the bottom profile of the near-shore from remote sensing data such as wave speed, wave frequency, and reflectivity. The PI and a graduate student will compare combinations of models with different levels of resolution and inverse problem methods with different costs. The PI will address problems in both implementation and analysis.

The Consortium for Advanced Simulation of Light Water Reactors, CASL, supports the broad national missions of enabling energy independence; supporting economic growth through the offering of superior technology ; and being good stewards of the environment, buy enabling predictive simulation of nuclear power plants. Such capability will make possible power uprates, lifetime extension and higher fuel burnups for currently operating and new Generation III+ nuclear power plants. This proposal is for work that ORNL will pay TN state takes on.

This proposal is for a very large amount of supercomputer time at NSF's Blue Waters supercomputer. This time will be used for advanced simulations and design of nanoscale materials and devices. The proposal also contains a request for travel funds to Blue Waters symposia and training events.

The PI will design, analyze, and implement algorithms for the solution of nonlinear equations and optimization problems. The research will focus on problems in which the functions and constraints are the outcomes of experiments or Monte Carlo simulations.

This proposal requests funds to continue development of massively parallel quantum simulations software, to adapt it for usage on multitude of computer architectures, including current and future petascale supercomputers, and to distribute it to user community.

Dye-sensitized solar cell (DSSC) are a relatively low-cost alternatives to more expensive crystalline silicone solar cells. DSSCs are composed of a high band-gap semiconductor with covalently attached photosensitizers that absorb visible sunlight and inject electrons into the conduction band of the semiconductor, thus generating electricity. Dyes based on ruthenium (Ru) polypyridine complexes are efficient, but Ru is rare, expensive, and toxic. We seek to design dyes based on iron, which is cheap, abundant and non-toxic. The main obstacle to the utilization of the initially excited photoactive states is their very short lifetime, which makes them very inefficient as dyes in DSSCs. This proposal aims to obtain a better theoretical understanding of structural features of Fe-based dyes that lead to the fast deactivation of their photoactive states, which is due to specific features of their potential energy surfaces.

This proposal requests travel funds to visit NCSA at U. Illinois Urbana-Champaign to work on optimizing our quantum simulation codes on the world's first sustained petaflops supercomputer, the Blue Waters. It also requests an allocation of supercomputer time on this machine.

The overall goal of this work is to produce a paradigm shift in the way that porous medium systems are understood and analyzed. The specific objectives of this work are: (1) to provide a robust foundation for model building based upon conservation principles and rigorous thermodynamics such that all variables and system dynamics can be considered across scale; (2) to detail a model-building approach that matches the sophistication of the model, in terms of dimensionality, resolution, and scale, with the sophistication needed to address a particular problem of interest; (3) to yield an approach with recourse if the appropriate match in sophistication between model and application is not supported by observation through a clear enumeration of assumptions and approximations that underpin a model; (4) to replace current empirical closure relations for capillary pressure, heat transport, thermal dispersion, and solid deformation with functional forms consistent with thermodynamics and functionally more complete in approximating the governing physics; (5) to validate the theory through sophisticated, high-resolution multiscale modeling that demonstrates the consistency of parameters employed across scales and with experiments; (6) to document the fundamental and rigorous approach employed so that the focus can be broadened to emerging areas of scientific interest; (7) to detail how the approach developed provides an appropriate basis on which to build sound stochastic models; (8) to engage and educate a broad group of international, interdisciplinary researchers that are motivated to learn the new theories and models that will be developed through this work and to apply these models to a wide range of biological, geological, medical, and engineering problems; (9) to provide a unique, diverse, and interdisciplinary environment in which to educate graduate students and post-doctoral associates; and (10) to ensure broader impacts of our work.

The Principal Investigator will continue his work in model calibration and fast solvers as applied to ground and surface water simulation. His research will focus on (1) POD models for nonlinear problems such as unsaturated subsurface flow and reactive transport and (2) multilevel and continuation methods for nonlinear equations. The proposed research will be done in collaboration with a group at the US Engineer Research and Development Center (ERDC). The Adaptive Hydrology model (ADH), a production groundwater modeling code, will be used as both a large-scale testbed for the algorithmic work in the project and as a source for new research topics. The work done by the PI and his students has had a direct impact on the evolution of ADH and we expect that the proposed program of basic research will have an impact on the future of the code.

The proposed collaborative research will adapt and develop novel computational algorithms and software to enable very large scale simulations on future sustained petaflops supercomputers.

The PI will extend his work on fast parallel solvers for the Wigner-Poisson equation to devices with nonsymmetric barriers, models with boundary conditions which contain quantum effects, and molecular devices with potentials coming from molecular dynamics.