Capability enhancement for stereoscopic particle image velocimetry system

立体粒子图像测速系统能力增强

• 批准号: 344682-2007
• 负责人: Sumner, David
• 金额: $ 3.62万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments - Category 1 (<$150,000)
• 财政年份: 2006
• 资助国家: 加拿大
• 起止时间: 2006-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=326280
• 关键词: Capability; enhancement; stereoscopic; particle; image

Stereoscopic particle image velocimetry (SPIV) is a laboratory instrument for measuring flow velocity in wind tunnels, towing tanks, and water channels.  SPIV uses a pair of powerful pulsed lasers to produce a laser light sheet, which illuminates seeding particles introduced into the flow.  A pair of digital cameras, aligned obliquely to the flow in a stereoscopic configuration, is synchronized with the lasers to photograph the flow containing the seeding particles.  Using computer software, a sequence of digital images of the flow is transformed into a time series of velocity vector fields.  In each field, the complete velocity vector is obtained at hundreds of points, giving an instantaneous picture of the fluid motion.  The velocity fields are analyzed to study how the flow behaves in space and time.  The method can be applied to very complex flows, including those that are unsteady, rotating, reversing, or turbulent.     The applicant uses SPIV for research in bluff-body aerodynamics and fluid-structure interactions. This research is important in the engineering design of buildings, chimneys, and offshore structures.  The study of these flows is motivated by industrial concerns related to flow-induced vibrations, turbulent buffeting, aerodynamic drag, dispersal of pollutants from stacks, and the safety of hydraulic structures.     The proposed equipment will significantly enhance the measurement and analysis capabilities of the applicant's existing SPIV system. The original system, which was acquired in 2000, was one of the first commercially available SPIV systems and the first of its kind in Canada.  With rapid development and maturation of this technology, a three-fold capability enhancement is now proposed for the existing SPIV infrastructure: (i) new higher-resolution digital cameras, to increase the spatial resolution of the velocity fields and resolve smaller flow structures; (ii) new high-speed camera interface and computer, to increase the data acquisition rate and duration of the experiments; and (iii) new analysis software, with the Proper Orthogonal Decomposition technique, to improve the analysis of turbulent vortex structures in space and time.

立体粒子图像测速仪（SPIV）是一种用于测量风洞、拖曳水池和水槽中流速的实验室仪器。SPIV使用一对强大的脉冲激光器产生激光光片，照射引入流中的播种粒子。一对数码相机，以立体配置倾斜于流中，与激光同步，拍摄包含种子颗粒的流动。使用计算机软件，将流动的数字图像序列转换为速度矢量场的时间序列。在每个场中，在数百个点处获得完整的速度矢量，给出流体运动的瞬时图像。分析速度场以研究流体在空间和时间上的行为。该方法可应用于非常复杂的流动，包括不稳定、旋转、反向或湍流。 申请人使用SPIV进行钝体空气动力学和流体-结构相互作用的研究。这一研究在建筑物、烟囱和近海结构物的工程设计中具有重要意义。对这些流动的研究是由与流致振动、湍流抖振、空气动力阻力、烟囱污染物的扩散以及水工结构物的安全性有关的工业关注所激发的。 拟议的设备将大大提高申请人现有SPIV系统的测量和分析能力。2000年购置的原始系统是最早投入商业使用的SPIV系统之一，也是加拿大的第一个此类系统，随着这项技术的迅速发展和成熟，现在建议对现有的SPIV基础设施进行三方面的能力增强：（i）新的高分辨率数字摄像机，以提高速度场的空间分辨率并分辨较小的流动结构;（ii）新的高速摄影机接口和计算机，以提高数据采集速度和实验持续时间;（iii）新的分析软件，采用本征正交分解技术，以改进对湍流涡流结构在空间和时间上的分析。