Tomographic Particle Image Velocimetry System

拟议研究的重点是对各种工程系统中出现的复杂分离流进行定量成像，包括船用螺旋桨，天然气运输管道，波浪能设备和风力涡轮机。这些应用的特点是高度三维流动，这在计算建模和实验表征方面提出了艰巨的挑战。** UVic流体力学实验室采用了粒子图像测速技术（PIV），以获得全球定量流动模式，从而提高对流体流动的理解。PIV的实施包括用示踪粒子对流动进行播种，获取由脉冲激光照射的粒子图像，以及对所得速度矢量图案进行后处理。虽然这种基于图像的方法提供了大量的洞察流物理，本实验系统的局限性之一是，它只能记录到激光片的平面的速度矢量的投影。越来越广泛的PIV应用需要更多的面外速度分量的知识。恢复完整速度分量的最常见方法之一是使用额外的摄像机从不同的观察方向进行额外的PIV记录，通常称为层析PIV。所要求的设备将包括一台高速数码相机、一台激光和层析PIV校准硬件和软件。这些设备将大大提高实验能力，扩大共同申请人目前进行的研究的实际应用范围。所要求的设备将使研究生在工程系统设计的各个方面的培训，以及在国家的最先进的实验技术的应用提供了重要的机会。

The focus of the proposed research is quantitative imaging of complex, separated flows that occur in a wide range of engineering systems, including marine propellers, gas transport pipelines, wave energy devices and wind turbines. These applications are characterized by highly three-dimensional flows, which present formidable challenges in terms of computational modelling and experimental characterization. ******A technique of particle image velocimetry (PIV) has been implemented at the Fluid Mechanics Laboratory at UVic to obtain global, quantitative flow patterns that lead to improved understanding of the fluid flow. Implementation of PIV involves seeding of the flow with tracer particles, acquisition of images of the particles that are illuminated by a pulsed laser, and post-processing of the resultant patterns of velocity vectors.******While this image-based approach provides substantial insight into the flow physics, one of the limitations of the present experimental system is that it is only capable of recording the projection of the velocity vector into the plane of the laser sheet. An increasingly wide range of PIV applications require additional knowledge of the out-of-plane velocity component. One of the most common approaches to recovering the complete set of velocity components involves additional PIV recording from a different viewing direction using an additional camera, which is generally referred to as tomographic PIV.******The requested equipment will include a high-speed digital camera, a laser and tomographic PIV calibration hardware and software. This equipment will significantly enhance the experimental capabilities and expand the range of practical applications of the current research undertaken by the co-applicants. The research that will be enabled by the requested equipment presents significant opportunity for the training of graduate students in various aspects of design of engineering systems as well as in application of the state-of-the-art experimental techniques.