Method and system for obtaining fluid flow directions of tundish water model

Patent metadata

Field	Value
Publication number	US-12450757-B1
Application number	US-202519009062-A
Country	US
Kind code	B1
Filing date	Jan 3, 2025
Priority date	Jan 12, 2024
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

A method and a system for obtaining fluid flow directions of a tundish water model are provided, and the method includes the following steps: building the tundish water model with a preset similarity ratio with a tundish prototype; carrying out an ink diffusion experiment in the tundish water model, and shooting a video of an ink diffusion process; carrying out a binarization processing on the video of the ink diffusion process frame by frame to obtain binarized images; obtaining a time grayscale map based on grayscale values of the binarized images; obtaining a velocity vector map of the tundish water model based on grayscale gradients of the time grayscale map; and obtaining a moving direction of the ink based on the velocity vector map, and obtaining a flowing direction of fluid in the tundish water model based on the moving direction.

First claim

What is claimed is:

1. A method for obtaining fluid flow directions of a tundish water model, comprising following steps:
building the tundish water model with a preset similarity ratio with a tundish prototype;
carrying out an ink diffusion experiment in the tundish water model, and shooting a video of an ink diffusion process;
carrying out a binarization processing on the video of the ink diffusion process frame by frame to obtain binarized images;
wherein a method for obtaining the binarized images is as follows:
obtaining a frame at a moment before adding ink in the video of the ink diffusion process;
subtracting RGB values of each frame at a moment after adding the ink from RGB values of the frame at the moment before adding the ink to obtain RGB results;
obtaining images with background removed based on a range value of RGB and the RGB results;
re-obtaining ink distribution maps at different moments based on the images with the background removed; and
assigning values to different grayscale areas in the ink distribution maps at different moments based on a preset grayscale threshold to obtain the binarized images;

obtaining a time grayscale map based on grayscale values of the binarized images;
wherein a method for obtaining the time grayscale map is as follows:
concentrating the binarized images of the ink distribution maps at different moments on an image according to the grayscale values increasing with time to obtain the time grayscale map;

obtaining a velocity vector map of the tundish water model based on grayscale gradients of the time grayscale map; and
obtaining a moving direction of the ink based on the velocity vector map, and obtaining a flowing direction of a fluid in the tundish water model based on the moving direction;
wherein a method for obtaining the moving direction of the ink is as follows:
carrying out finite splitting on pixels of the time grayscale map to obtain a plurality of grids;
calculating a grayscale average value of each of the grids;
based on the grayscale average value, adopting a principle of minimum grayscale gradient, and obtaining a grid with a minimum grayscale value as a first grid within a preset grid range;
comparing grayscale gradients of a grid opposite to the first grid to obtain a grid with a smallest grayscale gradient with the first grid as a second grid; and
connecting an arrow between the first grid and the second grid to obtain the moving direction of the ink.

2. The method for obtaining the fluid flow directions of the tundish water model according to claim 1 , wherein the preset similarity ratio comprises a preset geometric similarity ratio and a preset dynamic similarity ratio;
the preset geometric similarity ratio enables geometric dimensions of the tundish prototype and the tundish water model to meet a preset ratio; and
the preset dynamic similarity ratio enables Froude numbers of the tundish prototype and the tundish water model to be same.

3. The method for obtaining the fluid flow directions of the tundish water model according to claim 2 , wherein a formula of the preset dynamic similarity ratio is as follows:

Fr
m

=

v
m
2

g
m

⁢

L
m

=

v
p
2

g
p

⁢

L
p

=

Fr
p

,

in the formula, ν is fluid velocity; g is acceleration of gravity; L is characteristic length; m stands for the tundish water model, p stands for the tundish prototype, and Fr is Froude number.

4. A system for obtaining fluid flow directions of a tundish water model, wherein the system is used for realizing the method according to claim 1 , comprising:
a model building module, used for building the tundish water model with the preset similarity ratio with the tundish prototype;
a diffusion experiment module, used for carrying out the ink diffusion experiment in the tundish water model, and shooting the video of the ink diffusion process;
a binarization processing module, used for carrying out the binarization processing on the video of the ink diffusion process frame by frame to obtain the binarized images;
a grayscale module, used for obtaining the time grayscale map based on the grayscale values of the binarized images;
a velocity vector map obtaining module, used for obtaining the velocity vector map of the tundish water model based on the grayscale gradients of the time grayscale map; and
an ink moving direction obtaining module, used for obtaining the moving direction of the ink based on the velocity vector map, and obtaining the fluid flow directions in the tundish water model based on the moving direction.

5. The system for obtaining the fluid flow directions of the tundish water model according to claim 4 , wherein the binarization processing module comprises:
a frame obtaining unit, used for obtaining a frame at the moment before adding the ink in the video of the ink diffusion process;
an RGB obtaining unit, used for subtracting the RGB values of each frame at the moment after adding the ink from the RGB values of the frame at the moment before adding the ink to obtain the RGB results;
a background removing unit, used for obtaining the images with the background removed based on the range value of RGB and the RGB results;
an ink distribution map obtaining unit, used for re-obtaining the ink distribution maps at different moments based on the images with the background removed; and
a binarization unit, used for assigning the values to different grayscale areas in the ink distribution maps at different moments based on the preset grayscale threshold to obtain the binarized images.

Assignees

• Univ North China Technology
• Univ Beijing Science & Technology
• Univ Northeastern

Inventors

• Zhang Lifeng
• Duan Haojian
• Li Dinghan
• Ren Ying

Classifications

• G01P5/001

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• G06F2113/08

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• G06F30/28 Primary

  using fluid dynamics, e.g. using Navier-Stokes equations or computational fluid dynamics [CFD] · CPC title

• G06T2207/20224

  Image subtraction · CPC title

• G06T2207/10024

  Color image · CPC title