High Fidelity Modeling and Simulation of Turbulent Flame Spread Over Charring Materials

1033328 DesJardin这项提议的目标是开发一个先进的建模和模拟框架，用于预测火灾蔓延。该模拟基于大涡模拟(LES)技术，使用了新开发的嵌入式FAME扩展建模(EFSM)方法，该方法将在湍流FAME扩展预测中产生前所未有的精度。这种新的建模方法的验证和验证以及向公众传播知识将通过与美国政府和专门从事火灾科学的行业实验室的大力合作来促进。具体来说，涉及的机构是桑迪亚国家实验室(SNL)的消防科学和技术部，以及工厂共同全球研究(FM Global)。这些合作将导致：(1)将创建一个门户网站，用于下载和使用欧洲密克罗尼西亚联邦图书馆；(2)布法罗大学将在这项工作的第二年举办一个知名度传播讲习班。在这项研究中开发的所有工具和建模方法将通过P.I.目前教授的火灾科学和安全工程课程纳入课堂。智力价值：这项研究的智力价值在于，它具有统一的预测计算能力，可以预测烧焦材料上的湍流扩散。(1)基于EFSM的湍流壁面火灾预测的新方法；(2)考虑建筑材料炭化的热模型；(3)计算浮力驱动的湍流反应边界层的新的近壁边界模型和标度理论。这些模型的实现将被结合到现有的高精度流体-结构计算框架中，用于使用直接数值模拟(DNS)和大涡模拟(LES)来模拟耦合的热质传递。这些模型的加入将需要在大规模并行计算机上使用的数值算法进步，这将导致预测湍流火焰传播的时间和空间分辨率达到前所未有的水平。这些进展包括：(1)用于计算固-气界面共轭传热传质过程的自适应网格加密方法和(2)用于计算复杂几何形状的参与辐射换热的新的嵌入式切割单元方法。广泛的影响：这项研究对社会的影响是为大规模结构火灾的发展提供科学的见解。这项研究的长期影响是提供一个高保真、基础广泛的计算工具，以预测火灾结构的性能，并提供一支能够使用这些工具进行高性能计算的训练有素的劳动力。预期这些努力将为确保关键基础设施的消防安全的新的基于性能的设计方法提供建议。此外，作为本研究的一部分，开发的基础广泛的数学、建模和仿真框架不仅适用于火焰传播建模，还可以用于分析广泛的能量转换问题，这些问题涉及反应流动的流固耦合传热和传质过程。

1033328DesJardinThe objective of this proposal is to develop an advanced modeling and simulation framework for predicting fire spread. The modeling is based on Large Eddy Simulation (LES) techniques using a newly developed embedded fame spread modeling (EFSM) approach that will result in unprecedented accuracy in the prediction of turbulent fame spread. Validation and verification of this new modeling approach and dissemination of knowledge to the public will be facilitated by a strong collaboration with U.S. government and industry laboratories specializing in fire science. Specifically, the agencies involved are the Fire Science and Technology department at Sandia National Laboratories (SNL), and Factory Mutual Global Research (FM Global). These collaborations will result in: (1) a web-portal will be created for the downloading and using the EFSM library and (2) a fame spread workshop will be hosted by the University at Buffalo during the second year of the effort. All of the tools and modeling methods developed in this research endeavor will be incorporated into the classroom through a class the P.I. currently teaches on Fire Science and Safety Engineering.Intellectual Merit: The intellectual merit of this research is in a unified predictive computational capability to predict turbulent fame spread over charring materials. The modeling advancements for this effort are focused on: (1) a new modeling approach for predicting turbulent wall fires based on the use of EFSM, (2) a thermal model to account for charring of construction materials, (3) a new near-wall boundary model and scaling theory for computing buoyancy driven turbulent reacting boundary layers. The implementation of these models will be incorporated into an existing high-order accurate fluid-structure computational framework for simulating coupled conjugate heat and mass transfer using both direct numerical simulation (DNS) and LES. The inclusion of the models will require numerical algorithm advances for use on massively parallel computers that will result in unprecedented levels of time and spatial resolution for the prediction of turbulent flame spread. These advances include: (1) an adaptive mesh refinement procedure for computation of conjugate heat and mass transfer processes across solid-gas interfaces and (2) a new embedded cut-cell approach for computing participating radiation heat transfer in complex geometries.Broader Impact: The impact of this research on society is to offer scientific insight on the growth of large scale structural fires. The longer term impact of this research is to provide a high fidelity, broad-based computational tool, to predict the performance of structures from fire and a trained workforce who are able to use these tools for high performance computing. The expectation is that these efforts will provide suggestions for new performance based design approaches for insuring fire safety of critical infrastructures. In addition, the broad-based mathematical, modeling and simulation framework developed as part of this research is not unique to flame spread modeling and could also be used to analyze a wide range of energy-conversion problems which involve fluid-solid conjugate heat and mass transfer processes for reacting flows.