Three-dimensional flow field high-frequency measurement device based on light sheet scanning of particle pictures and method of three-dimensional flow field high-frequency measurement device

Abstract

The invention relates to a three-dimensional flow field high-frequency measurement device based on light sheet scanning of particle pictures and a method of the three-dimensional flow field high-frequency measurement device, and belongs to the research field of experimental fluid mechanics. The device comprises a laser, a rotating gear, a stepping motor, a cylindrical concave lens, a cylindrical convex lens, two high-speed cameras, a synchronizer and a computer, wherein the rotating gear is provided with N light reflecting teeth. The N thread-shaped light reflecting teeth are arranged on the cylindrical surface of the rotating gear at equal intervals and are in lap joint end to end, and in the rotating process, the rotating gear reflects an incoming laser beam with an invariable axis distance with the rotating gear into a reflected laser beam used for conducting unidirectional sequential scanning in a fixed plane, and the reflected laser beam is converted into a rectangular scanning light sheet after passing through the cylindrical concave lens and the cylindrical convex lens. Due to the fact that one-time scanning is achieved through each light reflecting tooth, the actual three-dimensional scanning speed of the device can be N times of the rotating speed of the stepping motor, high-frequency measurement of a three-dimensional flow field can be achieved actually, a spatial-temporal evolution process of the three-dimensional flow field is obtained, and significant application value is achieved for experimental research of the fluid mechanics.

Description

technical field [0001] The invention belongs to the research field of experimental fluid mechanics, in particular to a three-dimensional flow field high-frequency measurement device and method based on sheet light scanning particle images. Background technique [0002] The turbulence of water flow has strong temporal and spatial variation characteristics. For a long time, scientific and technological workers have used various methods to measure the three-dimensional flow field, such as three-dimensional velocity measurement technology on a two-dimensional plane, three-dimensional particle tracer velocimetry technology, defocused particle image Velocimetry technology, holographic particle image velocimetry technology, tomographic particle image velocimetry technology and sheet light scanning particle image velocimetry technology, etc. [0003] The three-dimensional velocity measurement technology on a two-dimensional plane is to use laser light to illuminate the tracer partic...

AI Technical Summary

Problems solved by technology

The three-dimensional velocity measurement technology on a two-dimensional plane can only obtain the three-dimensional flow velocity on a plane, but cannot obtain the real three-dimensional flow field in a volume

However, both the galvanometer method and the rotating drum method are limited by the rotation speed of the stepping motor and the manufacturing accuracy of the stepped mirror, and the frequency and range of sheet light scanning are relatively low. Therefore, the current sheet light scanning particle image velocimetry technology Small size, measurable flow rate and low sampling frequency

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