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

该奖项是根据2009年美国复苏和再投资法案（公法111 - 5）资助的。0846577HaselbacherThe研究目标，这项建议是使用预测模拟，采用创新的数值方法和最小的非线性，以了解管理混合流/粉雪雪崩（MA）的物理过程。MA由一个致密的核心和大雪粒的跃变层组成，在一个由小雪粒组成的稀湍流粉末云下面。 本提案的教育目标是开发科学和工程学中的预测模拟创新课程，并开发基于模拟的计算机游戏，向初中和高中学生教授流体力学概念。智力优势：拟议的预测模拟有可能改变我们对一般稀密多相流，特别是混合雪崩的理解。 模拟的变革性影响来自于自然发生或人工触发MA的全规模实验的危险性和遇到的困难，以及与较小规模实验相关的限制。从拟议的研究中获得的更好的理解将导致更准确地预测高度破坏性混合雪崩的大小，运行长度和危险地图，从而保护人类生命和基础设施。量纲分析是用来构建一个计算听话的模型，保留了重要的物理过程的相对缩放的全尺寸MA。预测模拟是基于一个创造性的和合理的方法耦合现有的模拟工具的致密的核心，跃变层，和粉末云，给一个创新的综合多相流模拟能力，也大大提高了雪崩模拟的最先进的。子尺度模拟将用于减少和量化模型尺度的不确定性。PI在计算多相流体动力学和大规模高性能计算方面具有独特的背景，能够执行模拟。与世界领先的雪崩研究机构之一瑞士联邦雪崩研究所的合作，确保获得全尺寸和模型尺寸雪崩的独特实验数据，以验证集成模拟代码并评估其预测能力。PI可以访问本地和国家高性能计算中心的资源，以执行拟议的模拟。更广泛的影响：本提案中描述的综合研究和教育计划将产生以下广泛的影响。首先，科学和工程预测模拟的创新高级课程将培训新一代科学家和工程师使用模拟作为虚拟实验。预测模拟将造福社会，因为它们允许对无法使用理论或实验研究的系统做出关键决策。其次，基于模拟的电脑游戏将与佛罗里达州纽贝里的橡树景中学的科学教师合作开发，以满足大部分经济困难的孩子的需求。这款电脑游戏将通过互联网传播，有可能接触到大量的初中和高中学生，激发他们从事科学和工程职业的热情，向他们介绍预测模拟的力量，并帮助他们掌握技能，根据想法在明天的经济中脱颖而出。第三，本科生将协助预测模拟和计算机游戏开发的研究，从而收集与现代计算方法的宝贵经验。作为综合研究和教育计划的一部分所取得的成果将在有关文献中发表。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).0846577HaselbacherThe 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.