0440253SukopRecent advances in lattice Boltzmann methods (LBMs) offer a radical new way of computing solutions to the challenging non-linear problems of concentration- and temperature-induced density driven flows. Interactions between low density fresh water and high density seawater in ground water flows in coastal regions illustrate the nature of the general problem. Ground water models for coastal areas must be able to simulate density driven flow and the coupled advection, diffusion, and dispersion of solutes and heat in porous media. Although LBMs are simpler than conventional (e.g., finite element) methods for these problems, they have not previously been applied to seawater intrusion problems. Because of the numerical difficulties inherent in conventional simulations involving non-linear, coupled solute/energy transport and density-driven flow, inconsistent numerical results have often been reported in the literature. Analytical solutions for the problems addressed by these models are rarely available, and 'validation' of various codes has generally relied on comparison with previous numerical results. As a completely different, more fundamental approach, LBMs may contribute significantly to clarifying these issues and offer a more robust and efficient means of solving these problems. We will compare LBM with conventional approaches for benchmark problems and develop code for larger, realistic problems.Intellectual merit of the proposed activityThis research is critical to advancement of knowledge and understanding of the hydrology of coastal aquifers, other salt-affected aquifers, and high-level (hot) waste disposal. Other disciplines where fluids and porous media are important could benefit.The PI and research team are uniquely qualified to conduct this project. The PI has conducted research on solute transport, pore- and macro-scale dispersion, and LBMs. The research team includes a computer scientist with expertise in LBMs, numerical methods, and parallel algorithms. Ample resources are available to conduct the project (see letters of support).Broader ImpactsThe proposed work will provide the beginning PI, the post-doctoral researcher, and graduate and undergraduate students with extensive experience in LBMs and existing models. The post-doc and students will receive intensive training. The project will lead directly to enhanced classroom and research experiences for students at FIU, which holds the Carnegie Foundation's highest rating (Doctoral/Research University-Extensive) and is a recognized Minority Serving Institution that awards more Bachelor's degrees to Hispanic students than any other U.S. university. Future students of the post-doc and graduate student will benefit. Career-long scientific partnerships will be established between the project participants. A new course in advanced solute transport modeling will be developed. Undergraduates will be recruited from the NSF GeoSCOPE project at FIU (see letter of support). The high-performance computing and algorithm development work will result in permanent infrastructure enhancement and modeling tools for the broad scientific community. Results will be broadly disseminated as refereed journal articles, presentations at scientific meetings, a dissertation, and via the Internet. Software will be available to interested researchers and ultimately as a modular option accessible from widely used model interfaces. Society will benefit from the enhanced ability of scientists and engineers to more accurately and rapidly predict density-driven flows arising from solute concentration and temperature variations such as those that affect millions of people who depend on ground water in coastal areas.
