A Surface Flow Field Measurement Method Based on Particle Image Velocimetry

Abstract

The invention discloses a surface flow field measuring method based on particle image speed measurement. The method comprises that tracer particles of undefined materials and sizes are dispensed in the surface of a flow field to be measured; the flow field to be measured is provided with at least one visual field, video images are sampled from the visual field, visual field rectification is carried out on the video images, and then corresponding bird's-eye views are established; each bird's-eye view is divided into multiple sub grids, and the flow speeds of corresponding sub grids in all the bird's-eye views are averaged to obtain a flow speed of the visual field; and data splicing and visualization are carried out on the flow speeds of multiple visual fields successively to A visualized flow speed image of the surface of the flow field to be measured. and a PIV technology is used to measure the flow speed of the surface flow field. The method has the advantages that a video collector is free in the visual angle, robustness for complex landform and external illumination is high, and requirements of different test environments can be met; the tracer particles of any type can be supported; and the analysis speed and the measuring precision are high.

Description

technical field [0001] The invention relates to the technical field of water conservancy measurement, in particular to a surface flow field measurement method based on particle image velocity measurement. Background technique [0002] Velocity measurement of surface flow field is an important means of river engineering model analysis, and also a basic technology in the field of water conservancy measurement. At present, the single-point flow velocity measurement device commonly used in the industry not only interferes with the flow field during measurement, resulting in measurement errors; but also because the measurement efficiency is too low, it is difficult to apply to the flow field analysis of large-scale river engineering models and unsteady flow. field analysis. [0003] Moreover, the existing surface flow velocity measurement methods mainly have the following disadvantages: (1) the video acquisition equipment must work at an angle perpendicular to the flow velocity ...

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Problems solved by technology

At present, the single-point flow velocity measurement device commonly used in the industry not only interferes with the flow field during measurement, resulting in measurement errors; but also because the measurement efficiency is too low, it is difficult to apply to the flow field analysis of large-scale river engineering models and unsteady flow. field analysis

[0003] Moreover, the existing surface flow velocity measurement methods mainly have the following disadvantages: (1) the video acquisition equipment must work at an angle perpendicular to the flow velocity surface, which requires high external lighting conditions, and the operation process is complicated; (2) multi-channel The data analysis speed is slow and the measurement accuracy is not high enough; (3) The cost of tracer particles used in most flow field velocity measurement systems is relatively high

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