Method using particle image velocimetry technology to measure sediment two-phase flow field

Abstract

The invention discloses a method using particle image velocimetry technology (PIV) to measure sediment two-phase flow field, and mainly used for inner flow velocity field measurement in a sediment two-phase flow fluid test; the method uses glass beads of high transparency to replace sediment particles of opacity or poor transparency; the glass beads mix with water or other liquid having similar refractive index with glass and excellent transparency so as to form a solid-fluid two-phase flow; the mixed solid-liquid two-phase flow is used for the fluid test, and the PIV technology is used for measuring the inner flow velocity field. The beneficial effects are that shooting image clearness of a PIV system can be improved in the sediment two-phase flow test, thus enhancing measuring precision, and realizing real time measurement of sediment two-phase flow inner flow velocity field with high concentration.

Description

[0001] technical field [0002] The invention belongs to the field of fluid testing and relates to a method for measuring fluid velocity field using particle image velocimetry (PIV), in particular to a method for measuring the internal flow velocity field of water-sand two-phase flow. Background technique [0003] Particle Image Velocimetry (hereinafter referred to as PIV) is a transient, full flow field, non-contact fluid image velocimetry technology developed in the late 1970s. The basic principle is: use a laser sheet light source to illuminate the plane to be observed in the fluid, and then take two images of the observation plane continuously by a high-speed camera. The position change of the tracer particles) and the shooting interval time are obtained to obtain the instantaneous flow velocity field of the observation plane (the default is that the tiny particles are consistent with the fluid motion). [0004] Two-phase flow composed of solid and liquid is a kind ...

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Problems solved by technology

[0005] As a relatively mature method of fluid velocity measurement, PIV technology has long been applied in various fluid experiments, but due to the high requirements on optical conditions, it is not suitable for water-sand two-phase flow (such as the muddy water part of sediment hyperpycnal flow) flow. The use of field measurement and other aspects has been greatly affected

The light intensity of the laser sheet light source will attenuate quickly when it is injected into the water-sand two-phase flow, resulting in a large difference in the brightness of the measurement plane; at the same time, the light transmittance in muddy water is poor, and the reflected light attenuates quickly after the measurement plane is illuminated. The particle image of the effect is very poor (such as figure 1 , 2 shown)

Therefore, usually only the low-density mixed phase can use PIV technology to measure the internal flow field. For hyperpycnal flow with high sand content and muddy water, only the flow field of clear water around the hyperpycnal flow can be observed when using PIV technology. The real-time planar flow field measurement in muddy water is still difficult. Very difficult

Therefore, the application of PIV technology in water-sand two-phase flow has been greatly limited.

[0006] At present, there is no relatively successful test method using PIV technology to observe the internal flow field of water-sand two-phase flow at home and abroad.

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