CAREER: Predictive Simulations of Dilute-Dense Multiphase Flows and Application to Mixed Avalanches

University Of Florida, Gainesville FL

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). 0846577 Haselbacher The research objective of this proposal is to use predictive simulations using innovative numerical methods and minimal empiricism to understand the physical processes that govern mixed flow/powder snow avalanches (MA). MA consist of a dense core and saltation layer of large snow particles beneath a dilute turbulent powder cloud of small snow particles. The education objectives of this proposal are to develop an innovative course on predictive simulations in science and engineering and to develop a simulation-based computer game to teach fluid mechanics concepts to middle and high school kids. Intellectual Merit: The proposed predictive simulations have the potential to transform our understanding of dilute dense multiphase flows in general and mixed avalanches in particular. The transformative impact of the simulations derives from the dangerous nature of and difficulties encountered in full scale experiments with naturally occurring or artificially triggered MA and the limitations associated with experiments at smaller scales. The improved understanding gained from the proposed research will result in more accurate predictions of the size, run out lengths, and hazard maps of highly destructive mixed avalanches and hence protect human lives and infrastructure. Dimensional analysis is used to construct a computationally tractable model of a full scale MA that retains the relative scaling of the important physical processes. The predictive simulations are based on a creative and rational approach of coupling existing simulation tools for the dense core, saltation layer, and the powder cloud to give an innovative integrated multiphase flow simulation capability that also greatly advances the state of the art in avalanche simulations. Subscale simulations will be used to reduce and quantify uncertainty at the model scale. The PI is uniquely qualified to perform the simulations given his background in computational multiphase fluid dynamics and large scale high performance computations. The collaboration with one of the worlds leading institutes for research on avalanches, the Swiss Federal Institute for Avalanche Research, ensures access to unique experimental data on full scale and model scale avalanches to validate the integrated simulation code and assess its predictive capability. The PI has access to resources at local and national high performance computing centers to carry out the proposed simulations. Broader Impacts: The integrated research and education plan described in this proposal will have the following broad impacts. First, the innovative advanced course on predictive simulations in science and engineering will train a new generation of scientists and engineers in using simulations as virtual experiments. Predictive simulations will benefit society because they allow critical decisions to be made with confidence for systems that cannot be studied using theory or experiments. Second, the simulation based computer game will be developed in collaboration with science teachers from Oak View Middle School in Newberry, FL that caters to a large percentage of financially disadvantaged kids. The computer game will be disseminated over the Internet and has the potential to reach a very large number of middle and high-school students, excite them about pursuing a career in science and engineering, introduce them to the power of predictive simulations and help provide them with the skills to excel in tomorrows economy based on ideas. Third, an undergraduate student will assist in the research on predictive simulations and the development of the computer game and therefore gather valuable experience with modern computational methods. The results obtained as part of the integrated research and education plan will be published in the relevant literature.