Development of an Advanced PIV System for Full-Field Flow Measurement

成功研制了一种基于高速CMOS相机、高速脉冲激光器和定时控制器的先进动态PIV系统。再增加一个CMOS摄像头，用一对国产的Scheinmpflug定位装置构建了一个立体PIV系统。该系统已应用于各种流场的全场流量测量。利用现有的动态PIV系统对水滴射流进行了测量。利用立体和动态PIV系统测量了以1800转/分的转速运行的PC冷却系统轴流风扇的下游流量。利用两台高速摄像机成功研制了一种具有高时间和空间动态范围的新系统，并将其应用于自由射流。利用立体动态piv的实验结果，分析了多孔喷管喷射气流的湍流和涡旋结构。建立了喷雾液滴尺寸和三维速度分量的同时测量技术。发展了复杂活体模型的无创立体定标技术，实现了非定常流量测量的高时空分辨率。动态PIV系统用于分析具有高度不稳定性和三维复杂性的动脉模型内脉动流。本文成功研制了一种扫描立体PIV，并将其应用于圆形射流和圆形撞击射流的三维速度和涡量分布的测量，在圆形射流的流动装置中安装了撞击平板。在停滞区观察到涡旋的伸展。所研制的动态PIV系统用于圆形冲击射流的时空测量。通过对所获得的湍流量进行评估，验证了测量结果。分析了滞止区湍流结构的时空行为，发现壁面附近高速流体团块的间歇性出现以及与之相关的横向涡旋结构的存在。动态PIV国际讲习班由本项目小组主持。少

An advanced dynamic PIV system has been successfully developed based on the combination of a high-speed CMOS camera, a high-speed pulse laser, and a timing controller. Adding another CMOS camera, a stereoscopic PIV system has been constructed with a pair of Scheinmpflug positioning devices (made in-house). The system has been applied to various flow fields for the full-field flow measurement.The water-droplet jet flow has been measured using the present dynamic PIV system. The flow downstream an axial flow fan for PC cooling system, rotating at 1,800 rpm, has been measured using the stereoscopic and dynamic PIV system.A new system with high dynamic ranges not only in time but also in space has been developed successfully by using two high speed cameras, and it was applied to a free jet flow..Turbulent and vortex structure of air jets issuing from a multi-hole nozzle have been analyzed using experimental results obtained by stereoscopic dynamic-PIV. And the technique of simultaneous mea … More surements of size and 3D velocity components of spray droplets has been established.Non-invasive stereo calibration technique for complicated living body models had been developed and highly temporal and spatial resolution of unsteady flow measurement is enabled. The dynamic PIV system is applied to analyze pulsatile flow inside the arterial model, which has highly instability and 3-dimensional complexity.A scanning stereoscopic PIV has been developed in success and was applied to measure the three-dimensional velocity and vorticity distribution of the round jet and the round impinging jet, where an impinging flat plate was installed in the flow apparatus of the round jet. Stretching of vortices in the stagnation region was observed.The dynamic PIV system developed has been used for the spatio-temporal measurement of a circular impinging jet flow of water. The measurement has been verified through an evaluation of turbulence quantities obtained. Spatio-temperal behaviors of turbulent structures in the stagnation region are analyzed, showing intermittent appearance of high-speed fluid lumps near the wall and the associated presence of transverse vortical structures.The International Workshop on Dynamic PIV was hosted by the present project group. Less