High Speed Visulization of Multphase Mixing

这是一个通用的流动可视化装置，它使用激光片和快速CCD相机来记录液滴的破裂和合并，多模态颗粒分布中的局部颗粒浓度，以及被动或反应标量的湍流混合。这是一个非常强大的工具，将大大扩大两个互补的研究小组的实验能力。Derksen教授研究多相流中的混合，重点是计算方法，特别是晶格玻尔兹曼方法。Kresta教授研究湍流混合问题，着重于实验和简化的工程模型，从而改进混合设备的设计。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。在过去的五年中，工业流体力学研究对实验的需求有所增加。与此同时，高速流动可视化的质量已向提供大量信息的高分辨率、定量数据发展。这些视频图像可以相对快速和廉价地收集，尽管数据的定量分析更复杂。在Derksen的小组中，可视化数据将为计算方法提供验证和指导。这些数据需要用于开发不能直接计算的特定现象的模型，验证计算方法，并在探索复杂过程时提出基本的物理现象。在Kresta的小组中，基于空间统计的图像分析技术将与特定混合问题的研究并行发展。预计这些方法将在燃烧和多相流以及与混合有关的具体问题上得到应用。高速可视化是一个强大的工具，它将极大地提高我们探测和理解这些复杂的和工业上重要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.