Tracer-particle-based non-contact density profile measuring method in internal wave experiment

Abstract

The invention discloses a tracer-particle-based non-contact density profile measuring method in an internal wave experiment. A PIV device is arranged at one side of a water tank. Saline water with thedensity lower than that of a tracer particle is placed on the bottom of the water tank and then saline water with the density higher than that of the tracer particle is placed, wherein the saline water contains tracer particles. Laser with the fixed wavelength and the fixed power irradiates the saline water with tracer particles mixed; the PIV device shoots an experimental observation area continuously; the tracer particles are displayed as white light points on an obtained grayscale image and the rest part is displayed in black; and on the basis of the number of white light points in a certain area on the grayscale image, the particle number is estimated by inversion and thus the water density is deduced. According to the method for acquiring velocity field and the density field information of an internal wave simultaneously by the PIV, the data consistency is high. The method can be applied to various marine fluid mechanics experiments.

Description

technical field [0001] The invention relates to the field of geophysical fluid mechanics model tests, in particular to a method for non-contact measurement of density profiles in internal wave experiments. Background technique [0002] Internal waves, a kind of wave that exists in the densocline inside the ocean, play an important role in the transport of matter and energy in the ocean. Internal wave experiments in laboratory tanks have become one of the main methods for scholars in related fields to explore internal waves . Among the published patent schemes, a variety of internal wave test schemes have been given at home and abroad, using ADV (Acoustic Doppler Velocimeter) to obtain single-point three-dimensional velocity data or PIV (Particle Image Velocimetry) to obtain plane two-dimensional The method of flow field data is very mature; when considering the point surface water density data, the C-T (salinity-temperature) probe is often used, but this is a single-point c...

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Problems solved by technology

Among the published patent schemes, a variety of internal wave test schemes have been given at home and abroad, using ADV (Acoustic Doppler Velocimeter) to obtain single-point three-dimensional velocity data or PIV (Particle Image Velocimetry) to obtain plane two-dimensional The method of flow field data is very mature; when considering the point surface water density data, the C-T (salinity-temperature) probe is often used, but this is a single-point contact measurement method, which will destroy the experiment to a certain extent In the stratified environment of water bodies; PLIF (planar laser-induced fluorescence technology) may be an option, but this method conflicts with PIV. It is difficult to obtain both data at the same time with ordinary methods, and it is difficult to ensure the repeatability of experiments for multiple experiments.

In addition, whether the data measured by different instruments have good consistency remains to be verified

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