基于特征点匹配的室内表面流场快速测量系统

为提升室内模型试验表面流场测量的计算效率，建立了基于图像特征点匹配的模型试验表面流场快速测量系统。该系统由摄像机、示踪粒子和测速软件组成，试验中首先投掷示踪粒子并采集试验视频，然后导入测速软件进行图像预处理和基于图像特征点匹配算法的快速测流计算并实时展示瞬时流场，最终输出原型尺度的时均流场及流线图。该系统应用于堰坝水闸工程模型试验和泄洪洞射流模型试验，系统自动化程度高，计算效率高，应用场景适应性强；输出的流场具有高时空间分辨率，精度与PIV相当，可真实反映出试验工况下表面水流特性。

New system for rapid measurement of indoor surface velocity fields based on feature matching velocimetry

To enhance spatial resolution and measurement efficiency, we present a novel system for measuring surface velocity fields of flows on large-scale hydraulic laboratory scale models. The basic idea is to match characteristic image features. To this end, flow is seeded with tracer and a camera is recording the scenery in plumb vertical top view in a height of 5 m. A matching algorithm correlates characteristic image feature points, and instantaneous and time-averaged velocity fields are provided automatically. Applications of the system to both weir flow and jet flow experiments yield reasonable velocity fields with high spatial resolution. This velocimetry system shows to be effective, efficient, and flexible. The output velocity field has high temporal-spatial resolution and keeps considerable accuracy with PIV, which can truly reflect characteristics of indoor surface flow.