MRI: Acquisition of a Digital Particle Image Velocimetry System for Studying Fluid Flow Around Organismal, Robotic and Marine Structures

MRI：获取数字粒子图像测速系统，用于研究生物体、机器人和海洋结构周围的流体流动

• 批准号: 1229193
• 负责人: Cheryl Wilga
• 金额: $ 20.7万
• 依托单位: University of Rhode Island
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1229193&HistoricalAwards=false
• 关键词: MRI; Acquisition; Digital; Particle; Image

Funds will be used to purchase a digital particle image velocimetry (DPIV) system that will enable students and researchers to visualize and quantify fluid flow around robotic biological, and marine structures using high-resolution video recordings. DPIV is an experimental technique for quantitatively visualizing fluid flow. The fluid medium is seeded with neutrally buoyant, reflective particles that are illuminated by a sheet of laser light. Particle movement is recorded by a camera, oriented perpendicular to the laser sheet. Vector fields are calculated by evaluating the cross-correlation between groups of particles in successive images. The requested DPIV system consists of a low-speed high-resolution camera (up to 30 frames/s, 1648x1214 pixel resolution, 512 MB onboard memory, 14-bit digital output, 7.4x7.4 µm pixels, LaVision Imager Pro X2M with PCII Frame Grabber), one high-speed high-resolution camera (1000 f/s at full resolution, up to 60,000 f/s at reduced resolution, 12 bit digital output, 2GB onboard memory, 1024x1024 pixel resolution, 17x17µm pixels, LaVision HighSpeedStar 3 GigE), and a high repetition laser (30 mJ/pulse @527nm at 1 kHz repetition rate, with integrated chiller). Camera lenses include a: 50 mm F/1.8 lens, 50mm F/1.4 lens, variable magnification 12X zoom Navitar lens, and a close-up zoom lens with an adaptor for microscopic use. Optics include an adjustable lens with focal length between 300-2000 mm, one -10 mm, and one -20 mm focal length lens with anti-reflection coating. Particles are near neutrally buoyant, reflective, hollow glass particles at a density of 15 mg/l. A camera is synchronized to record simultaneously with the laser through a timing unit managed by a control computer. A separate computer system runs each of the camera systems (low- and high-speed) and each system is capable of controlling the laser (quad-core processor PC, 2 GB Ram, 250 GB hard drive, RW DVD, 19" monitor, software and camera interface, LaVision). DaVis v.7 software, consisting of processing routines for 2D PIV/PTV (Particle Tracking Velocimetry), is used for image acquisition, processing, and hardware control. DaVis software allows calculation of velocity vectors and derivatives of the flow field along with the visualization of streamlines, jets, vortices and other fluid structures. The kinematics of flow structures are derived by compiling the images over time using ProAnalyst software for digitizing and 2D structure design. Quantitative flow visualization performed in specific projects will include characterizing fluid flow around shark fins, analyzing advective effects on plankton swimming and distributions, calculating friction and drag forces on SONAR components, characterizing flow separation on underwater vehicles and unsteady renewable energy devices, and determining drag effects due to biofilm formation and biofouling onsurfaces submerged in marine environments.The quantitative characterization of fluid flows is of fundamental importance in both natural and engineered systems, where the motion of fluid affects the morphology, function and ecology of organisms and determines the forces exerted on marine structures. The requested system is designed to enable experiments ranging from microscopic to macroscopic length scales, in a range of fluid flow regimes and supports research in engineering, life sciences and oceanography. The DPIV system will enable research projects studying the flow around robotic, marine structures, sonar components and biological systems ranging from bacteria and plankton to sharks. An interdisciplinary team including biologists, engineers and oceanographers at URI, Providence College, and Roger Williams University proposed an exciting set of research projects that examine the role of fluid flow in (1) the fluid flow around shark fins, (2) fluid effects on propulsion and predator prey interactions of gelatinous zooplankton, (3) fluid effects on the ecology and distribution of planktonic organisms, (4) tribological studies of friction and drag on SONR components, 5) drag and energy loss due to microbial growth on surfaces submerged in marine environments, and (6) local flow detection for feedback control of underwater vehicles and renewable energy devices. Acquisition of the DPIV system provides critical capabilities that strengthen RI higher education institutions' competitiveness in research and education. The system will be used in undergraduate and graduate courses and both undergraduate and graduate students and postdoctoral researchers will be trained to use the DPIV system in their research. Students benefit from this hands-on learning approach that relies on integrating basic scientific disciplines with mathematical and analytical approaches in a practical and intuitive manner.

资金将用于购买数字粒子图像测速（DPIV）系统，该系统将使学生和研究人员能够使用高分辨率视频记录来可视化和量化机器人生物和海洋结构周围的流体流动。 DPIV 是一种定量可视化流体流动的实验技术。 流体介质中注入了中性浮力的反射粒子，这些粒子被激光束照射。粒子运动由垂直于激光片的相机记录。 矢量场是通过评估连续图像中粒子组之间的互相关性来计算的。所需的 DPIV 系统包括一台低速高分辨率相机（高达 30 帧/秒、1648x1214 像素分辨率、512 MB 板载内存、14 位数字输出、7.4x7.4 µm 像素、带 PCII 图像采集卡的 LaVision Imager Pro X2M）、一台高速高分辨率相机（全分辨率下 1000 f/s，高达 60,000 f/s）在减少的 分辨率、12 位数字输出、2GB 板载内存、1024x1024 像素分辨率、17x17μm 像素、LaVision HighSpeedStar 3 GigE）和高重复激光器（30 mJ/脉冲 @527nm，1 kHz 重复率，带集成冷却器）。相机镜头包括：50 毫米 F/1.8 镜头、50 毫米 F/1.4 镜头、可变放大倍率 12 倍变焦 Navitar 镜头以及带有用于显微镜使用的适配器的近摄变焦镜头。光学器件包括一个焦距在 300-2000 毫米之间的可调透镜、一个 -10 毫米和一个 -20 毫米焦距且带有防反射涂层的透镜。颗粒接近中性浮力、反射性空心玻璃颗粒，密度为 15 毫克/升。相机通过由控制计算机管理的计时单元与激光同步记录。单独的计算机系统运行每个相机系统（低速和高速），每个系统都能够控制激光器（四核处理器 PC、2 GB RAM、250 GB 硬盘驱动器、RW DVD、19" 显示器、软件和相机接口、LaVision）。DaVis v.7 软件由 2D PIV/PTV（粒子跟踪测速）处理例程组成，用于图像采集、处理、 和硬件控制。 DaVis 软件可以计算流场的速度矢量和导数，以及流线、射流、涡流和其他流体结构的可视化。使用 ProAnalyst 软件进行数字化和 2D 结构设计，通过随时间编译图像来导出流动结构的运动学。 在特定项目中进行的定量流动可视化将包括描述鲨鱼鳍周围的流体流动特征、分析对流效应 浮游生物的游泳和分布，计算声纳组件上的摩擦力和阻力，表征水下航行器和非稳态可再生能源装置的流动分离，并确定由于海洋环境中生物膜形成和生物污垢在表面上形成的阻力效应。流体流动的定量表征在自然系统和工程系统中都至关重要，其中流体的运动影响着流体的运动。 生物体的形态、功能和生态，并决定施加在海洋结构上的力。所需的系统旨在实现从微观到宏观长度尺度、一系列流体流动状态下的实验，并支持工程、生命科学和海洋学方面的研究。 DPIV 系统将使研究项目能够研究机器人、海洋结构、声纳组件和生物系统周围的流动，包括 细菌和浮游生物对鲨鱼来说。 URI、普罗维登斯学院和罗杰威廉姆斯大学的生物学家、工程师和海洋学家组成的跨学科团队提出了一系列令人兴奋的研究项目，研究流体流动在以下方面的作用：(1) 鲨鱼鳍周围的流体流动，(2) 流体对胶状浮游动物的推进和捕食者猎物相互作用的影响，(3) 流体对胶状浮游动物的生态和分布的影响 浮游生物，(4) SONR 部件上的摩擦和阻力的摩擦学研究，5) 由于海洋环境中淹没的表面微生物生长引起的阻力和能量损失，以及 (6) 用于水下航行器和可再生能源设备反馈控制的局部流量检测。收购 DPIV 系统提供了增强 RI 高等教育机构在研究和教育方面竞争力的关键能力。该系统将用于 本科生和研究生课程以及本科生和研究生以及博士后研究人员将接受培训，在他们的研究中使用 DPIV 系统。学生可以从这种实践学习方法中受益，这种学习方法依赖于以实用和直观的方式将基础科学学科与数学和分析方法相结合。