This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
Many liquid/gas two-phase flows involve topology changes, where atomization of the liquid is governed by the dynamics of the phase interface. Although atomization is crucial in many technical applications ranging from energy conversion to pharmaceutical sprays, no predictive models derived from first principle currently exist. Development of such a predictive model using large eddy simulations (LES) for atomizing flows is the objective of this research. Since the phase interface dynamics during atomization do not appear to follow a cascade process, a novel approach is planned to determine the unclosed terms in the LES formulation involving the phase interface dynamics. This approach, based on a multi-scale decomposition, combines features of direct numerical simulations (DNS) and LES that inherently incorporates the interaction and competition between different forces and atomization mechanisms acting on multiple length and time scales. While the focus of this project is on liquid/gas interfaces, the planned methodology can be applied to other thin, interface-like structures that may or may not follow a cascade process, such as premixed and partially premixed flame fronts. All solvers and models developed in the project will be made freely and readily available. Being based on the CHIMPS paradigm, adaptation to other researcher's codes is straightforward, thus ensuring wide dissemination of the project's results. This efficient, predictive LES approach for atomization has the potential to initiate a transformative, bold new design philosophy, because the cost of pre-selection feasibility studies using the LES approach is significantly lower than experimental studies. This study will incorporate results into a new cross-listed graduate/advanced undergraduate course to be developed by the PI on multiphase flows. Projects developed in the courses will help recruit undergraduates into REU projects that will focus on supporting and enhancing a high school outreach program. The investigators will collaborate with the Scottsdale Unified School District to involve high school calculus and physics students in experimental research by designing, testing, analyzing, and optimizing water hose nozzles to meet different goals. The best designs will then be analyzed experimentally in the Biopropulsion Laboratory at ASU, and will also be analyzed numerically with the models and tools developed in this project with the REU students. The high school students will tour the ASU Biopropulsion Laboratory and monitor the experiments in their classrooms via two webcams that are remotely controlled.
