Collaborative Research: Dynamics and Stability of Metallic Foams: Network Modelling

该奖项的研究目标是发展一种通过冻结液体/气体泡沫来制造多孔金属构件的工艺和理论。液体泡沫的一个主要问题是相邻的气泡非常迅速地（毫秒）结合在一起，使泡沫变成一个大气泡。在这项研究中，将设计和建模一个连续的过程，使气泡冻结到位，在固体中形成均匀的孔隙阵列。要做到这一点，必须研究液体泡沫中的流体流动和热传递，确定不同物理过程发生的速率，并设计出控制这些过程的方案。将构建多泡泡沫的数学表示，以监测泡沫如何变粗，并确定冻结材料的最佳方法。渐近方法，数值模拟和分析相结合，提出实验，以产生过程的概念证明。如果这项工作成功，预计将产生一种多孔金属，这种金属与类似的固体一样坚固或更坚固，但重量只有固体的十分之一。这些材料将用于制造飞机、火箭、轮船和汽车。这项研究将使创造具有精确控制孔隙度的金属成为可能，并将影响对包含大量尺度的自由边界问题所控制的复杂非线性物理现象的理解。这项研究对社会的潜在长期影响将包括提高能源效率、环境清洁、安全和节约物质资源。该项目由材料加工和制造（MPM）项目、土木、机械和制造创新（CMMI）部门、流体动力学项目、化学、生物工程、环境和运输系统（CBET）部门以及工程理事会（ENG）提供的支持部门间研究的资金共同资助。

The research objective of this award is to develop a process and theory for making members of porous metals by the freezing of liquid/gas foams. A primary problem with liquid foams is that adjacent bubbles coalesce very rapidly (milliseconds) turning the foam into one large bubble. In this investigation a continuous process that freezes the bubbles in place creating a uniform array of pores within the solid will be designed and modeled. To accomplish this one must study the fluid flow and heat transfer in liquid foams, determine the rates at which different physical processes occur and devise a protocol for the control of these. A mathematical representation of a multi-bubble foam will be constructed to monitor how the foam coarsens and to determine the best way to freeze the material. Asymptotic methods, numerical simulation and analysis will be combined to suggest experiments to yield proof of concept of the process.If successful this work is expected to result in a process to create porous metals that are as strong or stronger than the comparable solid but with one-tenth the weight. Such materials would be useful in the manufacture of airplane, rockets, ships, and automobiles. This research will enable the creation of metals of precisely controlled porosity and will impact the understanding of complex, nonlinear physical phenomena governed by free boundary problems containing a large expanse of scales. The potential, long-term impact of the research in society will include improvements in energy efficiency, environmental cleanliness, safety, and conservation of material resources.This project is jointly funded by the Materials Processing & Manufacturing (MPM) Program, of the Civil, Mechanical, and Manufacturing Innovation (CMMI) Division, by the Fluid Dynamics Program, of the Chemical, Bioengineering, Environmental, and Transport Systems (CBET) Division, and by funding provided from the Directorate for Engineering (ENG) to support Inter Divisional Research.