CAREER: Measurement and Analysis of Particle/Turbulence Interaction within Two-Phase Flows

研究目标是通过详细的实验、分析和模拟，了解分散系统中质量、动量和能量如何交换，从而提高对稀、分散、两相流中粒子-湍流相互作用的认识状态。将开发能够同时测量三维体积内粒子浓度、粒子速度和流体速度的新仪器。利用高速铜蒸气激光器、扫描光学器件和鼓式相机，构建扫描粒子图像测速仪，测量两相的两个速度分量和测量体积内多个平面上的粒子浓度。这些测量将提供与湍流流体结构有关的颗粒组织的详细信息，其特征是颗粒和流体速度以及颗粒浓度的相互关联。将进行实验来研究均匀湍流中重颗粒的耦合影响，以提供目前文献中无法获得的实验验证，详细说明无组织湍流中颗粒/流体耦合的性质。实验将在可与以前的数值模拟直接比较的条件下进行，并将这些条件扩展到目前无法通过计算解决的情况。本研究的结果将对许多使用两相分散系统的工程领域产生影响，如喷雾燃烧、颗粒沉淀、喷雾干燥、沉积物输送和云物理。教育目标是发展一种综合的工程教学方法，将设计过程的要素与基础教学相结合，提供联系。作为致力于实现这一目标的一个例子，建议在当前的本科流体和热科学课程中增加设计部分，以增强学生对开放式问题解决的接触，并通过与相关应用的联系增加他们对该主题的理解和兴趣。

ABSTRACT CTS-9702723 Kenneth T. Kiger University of Maryland The research objective is to advance the state of knowledge concerning particle-turbulence interaction in dilute, disperse, two-phase flows, through progress in understanding how mass, momentum and energy is exchanged in dispersed systems by detail experimentation, analysis, and simulation. New instrumentation which will enable the simultaneous measurement of particle concentration, particle velocity and fluid velocity within a three-dimensional volume will be developed. A scanning particle image velocimeter will be constructed using a high-speed copper-vapor laser, scanning optics, and a drum camera to measure two velocity components of both phases and the particulate concentration on multiple planes within the measurement volume. The measurements will provide detailed information about the organization of particulates in relation to the turbulent fluid structure, as characterized by cross-correlations of the particle and fluid velocity and particle concentration. Experiments will be conducted to study the coupling influence of heavy particulates within homogeneous turbulence to provide experimental validation currently unavailable in the literature that details the nature of the particle/fluid coupling within an unorganized turbulent flow. The experiments will be conducted under conditions that will allow direct comparison with previous numerical simulations and the conditions will be extended to those regimes currently inaccessible to computational solution. Results from this research will have impact upon many engineering fields which utilize two-phase dispersed systems such as spray combustion, particulate precipitators, spray drying, sediment transport, and cloud physics. The educational objective is to develop an integrated approach to engineering instruction that will provide connectivity to elements of design processes in conjunction with fundamental instruction. As an example of a commitment toward this goal, i t is proposed that a design component be added to the current undergraduate fluid and thermal sciences curriculum, to enhance the students' exposure to open-ended problem-solving and increase their understanding and interest in the topic through connection with relevant applications.