High Speed Visulization of Multphase Mixing

这是一个通用的流动显示装置，它使用激光薄片和快速CCD摄像机来记录液滴的分解和合并、多模式颗粒分布中的局部颗粒浓度以及被动标量或反应标量的湍流混合。这是一个非常强大的工具，将极大地扩展两个互补研究小组的实验能力。德克森教授研究多相流中的混合，重点是计算方法，特别是格子玻尔兹曼方法。克雷斯塔教授研究湍流混合问题，重点是实验和简化的工程模型，这将导致混合设备设计的改进。两位教授都热衷于增加我们对中尺度混合的物理理解，特别是在多相系统中。在过去的五年里，对面向工业的流体力学研究中的实验的需求有所增加。同时，高速流动显示的质量也向着高分辨率、提供大量信息的定量数据方向发展。这些视频图像可以相对快速和廉价地收集，尽管对数据的量化分析涉及更多。在德克森的团队中，可视化数据将为计算方法提供验证和指导。需要这些数据来为无法直接计算的特定现象建立模型，验证计算方法，并在探索复杂过程时揭示基本的物理现象。在Kresta的团队中，基于空间统计的图像分析技术将与对特定混合问题的研究并行开发。预计这些方法将在燃烧和多相流以及与混合相关的问题上得到应用。高速可视化是一个强大的工具，将极大地提高我们探索和理解这些复杂和具有工业重要性的多相流现象的能力。

This proposal is for a general purpose flow visualization setup which uses a laser sheet and fast CCD camera to record the break-up and coalescence of droplets, local concentration of particles in multi-modal particle distributions, and the turbulent mixing of a passive or reacting scalar. This is a very powerful tool which will significantly expand the experimental capabilities of two complementary research groups.  Prof. Derksen studies mixing in multiphase flows with an emphasis on computational methods, and in particular the lattice Boltzmann approach.  Prof. Kresta studies turbulent mixing problems, with an emphasis on experiments and simplified engineering models which lead to improvements in mixing equipment design.  Both professors are passionate about increasing our physical understanding of mixing at the mesoscales, particularly in multiphase systems.  The need for experiments in industrially oriented fluid mechanics research has increased over the last five years. At the same time, the quality of high speed flow visualization has evolved towards high resolution, quantitative data that provide a great deal of information. These video images can be collected relatively quickly and inexpensively, although the quantitative analysis of the data is more involved.  In Derksen's group, the visualization data will provide validation and guidance for computational approaches. These data are needed to develop models for specific phenomena that can not be directly computed, to validate computational approaches, and to bring out the essential physical phenomena when exploring complex processes.  In Kresta's group, image analysis techniques based on spatial statistics will be developed in parallel with research on specific mixing problems. It is anticipated that these methods will find application in combustion and multiphase flows as well as on problems specifically related to mixing.  High speed visualization is a powerful tool which will dramatically improve our ability to probe and understand these complex and industrially important multiphase flow phenomena.