MRI: Development of an Intensified KHz Rate Plenoptic Camera System for 3D Flow Diagnostics

从通过人工心脏瓣膜的血液流动到现代喷气发动机中燃料和空气的混合燃烧，许多流动都是不稳定的三维流动。然而，用于研究、测试和评估这些流场的现代诊断方法是缓慢的、二维的，或者在多摄像头3D诊断的情况下，既昂贵又复杂。在这个项目中，研究小组将开发一种新的成像系统，能够在实际流场中使用单个相机进行高速3D测量。与复杂的多相机系统相比，开发的系统将更便宜，更紧凑，更容易安装，从而为世界各地的研究人员提供了一种易于使用且价格合理的工具来进行高速3D流量测量。该成像系统将用于了解心脑血管流动，推进高速车辆设计研究，并提高发动机和发电燃烧系统的燃烧效率。此外，这里开发的技术将与更广泛的研究界公开共享，以确保美国政府机构和行业的学生和研究人员都能使用。如此广泛的分布确保了开发的系统可以影响最广泛的应用范围，包括非定常的3D流体流动。这种诊断的基础是一个增强的全光学成像系统，能够以超过每秒1000帧的帧率测量3D标量和速度场。该系统由三个基本要素组成：(1)针对3D流量测量优化的kHz倍率增强全光相机和照明光源；(2)图像重建和速度估计算法，用于绘制体积图像和估计速度场；(3)在可接受的时间范围内处理所述数据的计算平台。该系统的开发将实现时间分辨、3D流量测量，包括颗粒图像测速、化学发光成像、激光诱导荧光和背景定向纹影成像。所提出的仪器是基于奥本大学研究人员建立的低帧率原型，该原型已被证明是一个简单、紧凑、健壮和有效的3D成像系统。该系统的模块化将允许系统针对不同的设施和技术进行优化，包括具有显着提高体积测量空间分辨率的立体全光诊断。

From blood flow through artificial heart valves to mixing and combustion of fuel and air in a modern jet engine, many flows are both unsteady and three-dimensional. Modern diagnostics used to study, test and evaluate these flow fields, however, are slow and two-dimensional or, in the case of multi-camera 3D diagnostics, expensive and complex. In this project, the research team will develop a new imaging system capable of making high-speed 3D measurements in practical flow fields using only a single camera. The developed system will be significantly cheaper, more compact, and easier to set up than complex multi-camera systems, thus providing researchers around the world with an accessible and affordable tool to make high-speed 3D flow measurements. This imaging system will be used to understand cardio- and cerebro-vascular flows, advance high speed vehicle design research, and improve combustion efficiency in engines and combustion systems for power generation. In addition, the technology developed here will be openly shared with the broader research community to ensure access for students and researchers across the U.S. government agencies and industries. Such wide distribution ensures that the developed system impacts the widest possible range of applications involving unsteady, 3D fluid flows.The basis for this diagnostic is an intensified plenoptic imaging system capable of measuring 3D scalar and velocity fields at framing rates in excess of 1,000 frames per second. The system consists of three essential elements: (1) a kHz rate intensified plenoptic camera and illumination source optimized for 3D flow measurements; (2) image reconstruction and velocity estimation algorithms to render volumetric images and estimate velocity fields; and (3) a computing platform that processes the data in an acceptable time frame. The development of this system will enable time-resolved, 3D flow measurements, including particle image velocimetry, chemiluminiscence imaging, laser induced fluorescence, and background oriented Schlieren imaging. The proposed instrument is based on a low frame-rate prototype built by investigators at Auburn University that has been demonstrated as a simple, compact, robust and effective 3D imaging system. The modularity of the system will allow the system to be optimized for different facilities and techniques, including stereo-plenoptic diagnostics with the potential to dramatically improve spatial resolution of volumetric measurements.