Multiphase mixing is common in everyday life, such as the stirring of sugar granules into coffee. Yet the interactions between the two separate phases (solid sugar and liquid coffee in this example) results in complex mixing processes that occur at both large and small length scales. In many engineering and natural applications, this mixing is induced by shock waves, resulting in rapid mixing and phase change. Understanding multiphase mixing processes can help scientists better understand natural problems like supernovae and volcanic eruptions, and improve engineering applications, such as steam turbines used to produce electric power and advanced jet engine designs used for military aircraft. This work will use a simplified experiment to study the role of particle characteristics (like size) in shock-driven mixing. Experimental measurements will be used to validate new models for multiphase mixing and to ensure the accuracy of computer simulations. These simulations can then be used to study additional problems in multiphase mixing. Additionally, this work will have a broader impact by preparing engineering students to be leaders in their careers and communities. This will be accomplished through several initiatives, including developing a high school classroom lesson on fluids mixing; recruiting and mentoring students from underrepresented groups; and organizing a national security research symposium to help students and faculty apply research toward national defense.
The research objective of this CAREER project is to test the hypothesis that shock-driven turbulent mixing can be enhanced by the inclusion of a prescribed multiphase component. This project will use an integrated experimental and simulation approach to develop a new theory establishing the relationship between small-scale particle-driven mechanisms and large-scale hydrodynamic mechanisms in strongly accelerated multiphase mixing with evaporation. Experiments will be performed in the PI?s shock tube facility where measurements of hydrodynamic and particle mixing will be made. Simulations will be performed using the PI?s previously developed particle models, validated by the experimental measurements. The work will be broken into three tasks: 1) Determine the effect of particle velocity relaxation time on hydrodynamic mixing; 2) Determine the effect of hydrodynamic mixing on particle evaporation; and 3) Determine the effect of vapor production on mixing from secondary accelerations. Using these measurements, the simulation particle models will be validated and used to explore additional experimentally inaccessible measures and a wider parameter space. Both experimental and simulation results will be used to develop and test new theory to predict gas and vapor/particle mixing in hydrodynamic and turbulent regimes.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
