High-uniformity sheet light device for particle image velocity measurement and velocity measurement system

Abstract

A high-uniformity sheet light device for particle image velocimetry relates to the field of flow field velocity non-contact measurement and comprises a diffractive optical element and a lens. The diffractive optical element and the lens are arranged in parallel, and the diffractive optical element is close to the collimation laser transmitter; collimated laser beams emitted by the collimated laser emitter pass through the diffractive optical element and the lens to form sheet light; one side, far away from the lens, of the diffractive optical element is provided with a plurality of square micro units used for phase modulation, and the square micro units have the same width but have a plurality of different step depths. The high-uniformity distribution of sheet light can be realized while the illumination intensity of the sheet light is ensured, the utilization rate of light energy is greatly improved, and the design can be carried out according to a specified sheet light illumination range. The velocity measurement system for particle image velocity measurementis realized based on a high-uniformity sheet light device, and can uniformly illuminate the whole measurement area and improve the image quality, so that the movement velocity of particles in fluid can be more accurately obtained.

Description

technical field [0001] The invention relates to the field of non-contact measurement of flow field velocity, in particular to a high-uniformity sheet light device and a velocity measurement system for particle image velocity measurement. Background technique [0002] In order to conduct in-depth theoretical research on many difficult problems in fluid mechanics (complex flow phenomena such as turbulent flow and unsteady flow), one of the most basic tasks is to measure the fluid qualitatively and quantitatively, so as to show the law of motion of the fluid. Among them, the velocity of the fluid is the most intuitive characterization parameter for the quantitative study of fluid motion. In recent years, under the promotion of the development of image processing technology and computer technology, the particle image velocimetry technology based on motion image calculation and analysis technology has been developed rapidly. It can measure the flow velocity distribution of the f...

AI Technical Summary

Problems solved by technology

One obvious technical defect of this technology is the inhomogeneity of sheet light, which will lead to inconsistent scattered light intensity of tracer particles, seriously reduce image quality, and affect subsequent image processing and final measurement accuracy

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