Micron-size particle autorotation speed test method and device in liquid swirling flow field

Abstract

The invention relates to a micron-size particle autorotation speed test method and device in a liquid swirling flow field, and provides the micron-size particle autorotation speed test method in the liquid swirling flow field. The method comprises the steps that (1) transparent or semi-transparent particles which are equal in diameter, are arranged in a center symmetry mode and are provided with two inner cores are selected as autorotation test particles; (2) a high-speed image pickup system is adopted for recording the two-dimensional movement process of the particles in the liquid swirling flow field, and an image sequence of particle movement is obtained; (3) the autorotation speed of the particles is determined by analyzing the overlapping and separating frequency of projections of the two inner cores in the particles in the obtained image sequence. The invention further provides the micron-size particle autorotation speed test device in the liquid swirling flow field.

Description

technical field [0001] The invention belongs to the field of liquid-solid two-phase flow testing, and relates to a method and a device for testing the rotation speed of micron-sized particles in a liquid swirl field. Specifically, it provides a method and device for testing the rotation speed of micron-sized particles in a liquid swirl field by using transparent or translucent particles with equal diameters and two inner cores arranged symmetrically in the center and a high-speed camera system. Background technique [0002] In the liquid-solid two-phase flow, while the suspended particles follow the fluid for macroscopic displacement movement, due to the velocity gradient in the flow field, the suspended particles are unevenly stressed, making them rotate around their own instantaneous axis. Many studies have shown that the rotational motion of particles around their own instantaneous axis not only affects their own motion characteristics, but also affects the solid phase pa...

AI Technical Summary

Problems solved by technology

In the past, on the one hand, researchers marked the surface of the particles, which resulted in the size of the rotation test particles not being too small, and the marking was also very difficult; on the other hand, they directly selected particles with distinguishable surface characteristics for research. However, this surface feature is not uniform, and the recognition degree is relatively low.

[0008] To date, no effective method has been developed in the art to measure the spin velocity of micron-sized particles in low-viscosity, high-Reynolds-number fluids in liquid-solid microcyclones

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