High Speed System for 3 dimensional measurement of velocity fields and particle or bubble trajectories

速度场的时间分辨测定是实验流体力学领域的重要研究内容之一。直到最近，速度矢量的第三维度才变得可访问，因为时间分辨方法是点或2D方法。特别是在湍流中，这代表了大多数应用，同时对所有三个速度分量进行正确的分析和时间分辨，这意味着具有高数据速率，是至关重要的。同样在两相流中，气泡和颗粒的运动、轨迹和形式的3D知识对于优化相关应用（例如鼓泡塔）是非常重要的。此类问题应使用所要求的系统。为此，从不同的角度使用多个高速相机来进行气泡、颗粒和浓度场的断层摄影粒子图像测速或断层摄影成像，然后在3D体积中重建。利用该系统，可以在高采集频率下对大量不同的流场（混合过程、分离过程、风道、水槽、鼓泡塔、脉动流等）进行详细的三维定量检测。

The time-resolved determination of velocity fields is one of the most important research areas in the field of experimental fluid mechanics. Only recently the third dimension of the velocity vector has become accessible, since time resolved methods where point or 2D methods. Especially in turbulent flows, which represent most of the applications, a correct analysis of all three velocity components simultaneously and time-resolved, that means with high data rate, is crucial. Also in two-phase flows, the 3d knowledge of movement, trajectories and form of bubbles and particles is of great importance for the optimization of relevant applications as e.g. bubble columns. The requested system shall be used for this kind of problems. For this, several high-speed cameras are used from different angles to do tomographic particle image velocimetry or tomographic imaging of bubbles, particles and concentration fields, that are then reconstructed in the 3D volume. With this system, a multitude of different flow fields (mixing processes, separation processes, wind channel, water channel, bubble columns, pulsating flows, …) can be examined quantitatively in detail and in three dimensions with high acquisition frequencies.