Collaborative Research: CDS&E Decision Framework for Predictive Simulation of Highly Non-Equilibrium Thermal Transport in Nanomaterials

合作研究：CDS

• 批准号: 1758004
• 负责人: Jayathi Murthy
• 金额: $ 16.84万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1758004&HistoricalAwards=false
• 关键词: Collaborative; Research; CDS& Decision; Framework

CBET 1404991/1404823/1404919Murthy (U Texas at Austin), Mahadevan (Vanderbilt), Strachan (Purdue)During the last few years, the ability to experimentally probe physical phenomena at the nanoscale has improved dramatically. Experimental techniques are producing detailed nanoscale data on heat transport in materials such as graphene and silicon, but there are significant questions about whether these data are being interpreted correctly. One issue is that the theory used to interpret these data is too simplistic for the highly non-equilibrium regimes involved. Another issue is that there is significant variability in nanoscale measurements because of the extremely small length and time scales involved. In order to use experimental data to improve theory, one must fully account for measurement uncertainty, statistical variability in nanoscale fabrication techniques, and variability in material properties, and develop a systematic way to identify knowledge gaps in current models using these uncertain data. In this project, we propose to merge two hitherto distinct fields, decision science and phonon transport simulation, to create the first-ever decision framework for the systematic development and improvement of nanoscale thermal transport theory. The work will impact a wide variety of consumer applications including microelectronics, energy conversion and energy storage. The research and simulation tools developed in the project will be disseminated to the research community and to the graduate and undergraduate programs at UT Austin, Purdue and Vanderbilt through Purdue's nanoHUB, along with educational modules and tutorials to help broaden use. All three schools will actively engage their existing and highly-effective programs to recruit women and underrepresented minorities into their research programs. UT Austin will draw undergraduate research projects from this work to integrate into their innovative 35-in-5 Women in ME initiative which aims to increase the percentage of women in their freshman Mechanical Engineering batch to 35% by 2018.The overall objective of this proposal is to develop a deeper understanding of highly non-equilibrium phonon transport in nanomaterials. During the last few years, as our ability to probe nanoscale thermal and electronic transport has improved, it has come to be recognized that non-equilibrium transport dominates the performance of many emerging nanotechnologies and measurement systems. Experimental techniques such as micro-Raman and micro Brillouin Light Scattering are producing detailed wave-vector resolved phonon transport data which must be interpreted correctly if their true potential is to be unleashed. Though theory and computational predictions are also being developed simultaneously, few direct comparisons of measurements and theory have been made at this granularity and there is little confidence that existing theories are adequate. The project will combine detailed models and experiments for optically-excited phonon transport in graphene, bulk and thin film silicon and other materials with a Bayesian decision framework to develop better theories, interpret emerging experiments correctly, design better experiments and simulations and to quantify the uncertainty in our predictions. A unique feature of the project is the use of classical molecular dynamics (MD) simulations to evaluate model form uncertainty in phonon transport simulations based on the semi-classical phonon Boltzmann transport equation (BTE). Furthermore, by exploiting unique micro-Raman and micro Brillouin Light Scattering measurements being performed UT Austin in a parallel NSF project, we will have a one-of-a-kind opportunity to obtain spatially and mode-resolved phonon transport data that can significantly improve the quality of our models.The research plan includes the use of a Bayesian framework to (i) quantify model form uncertainties due small-perturbation assumptions in the modeling of phonon scattering through calibration with molecular dynamics (ii) calibrate interatomic potentials to spatially and spectrally-

CBET 1404991/1404823/1404919穆尔蒂（德克萨斯大学奥斯汀分校），Mahadevan（范德比尔特），斯特拉坎（普渡大学）在过去的几年里，在纳米尺度上实验探测物理现象的能力已经大大提高。实验技术正在产生有关石墨烯和硅等材料中热传输的详细纳米级数据，但这些数据是否被正确解释存在重大问题。一个问题是，用于解释这些数据的理论对于所涉及的高度非平衡制度来说过于简单化。另一个问题是，由于涉及的长度和时间尺度非常小，因此纳米级测量存在显著的可变性。为了使用实验数据来改进理论，必须充分考虑测量的不确定性，纳米制造技术的统计变异性和材料特性的变异性，并开发一种系统的方法来使用这些不确定的数据来识别当前模型中的知识缺口。在这个项目中，我们建议合并两个迄今为止不同的领域，决策科学和声子输运模拟，创建有史以来第一个决策框架的系统发展和改进的纳米热输运理论。这项工作将影响各种各样的消费应用，包括微电子，能源转换和储能。该项目中开发的研究和模拟工具将通过普渡大学的nanoHUB传播给研究界以及UT Austin，Purdue和范德比尔特的研究生和本科生课程，沿着教育模块和教程，以帮助扩大使用范围。这三所学校都将积极参与现有的高效项目，招募女性和代表性不足的少数民族参加他们的研究项目。UT Austin将从这项工作中吸引本科生研究项目，以整合到他们的创新35-in-5女性ME计划中，该计划旨在到2018年将大一机械工程批次中的女性比例提高到35%。在过去的几年中，随着我们探测纳米级热和电子输运的能力的提高，人们已经认识到，非平衡输运主导了许多新兴的纳米技术和测量系统的性能。实验技术，如微拉曼和微布里渊光散射产生详细的波矢量分辨声子输运数据，必须正确解释，如果他们的真正潜力是释放。虽然理论和计算预测也在同时发展，但在这种粒度下，很少有测量和理论的直接比较，并且几乎没有信心认为现有的理论是足够的。 该项目将联合收割机结合详细的模型和实验，在石墨烯，块状和薄膜硅和其他材料中的光激发声子输运与贝叶斯决策框架，以开发更好的理论，正确解释新兴的实验，设计更好的实验和模拟，并量化我们预测的不确定性。 该项目的一个独特之处是使用经典分子动力学（MD）模拟来评估基于半经典声子玻尔兹曼输运方程（BTE）的声子输运模拟中模型形式的不确定性。此外，通过利用UT Austin在一个并行NSF项目中进行的独特的显微拉曼和显微布里渊光散射测量，我们将有一个独一无二的机会获得空间和模式分辨的声子输运数据，这可以显着提高我们模型的质量。 (i)量化模型形式的不确定性，由于小扰动假设， 通过用分子动力学校准的声子散射的建模（ii）校准原子间势以在空间和光谱上-