| It is a common phenomenon that gas-liquid two-phase flow around bluff body in industrial production. Researching vortex shedding in gas-liquid two-phase flow has important significance in providing a theoretical guarantee for the designation of industrial anti-vibration and accurately measuring the flow parameters in gas-liquid two-phase flow. In this paper, the characteristics of vortex shedding for vortex flowmeter under the conditions of gas-liquid two-phase flow in vertical pipe are studied by using a combination of experimental and numerical simulation method.They are completed as follows:1. First to analysis the experimental signal measurement error, it increases as the percentage of liquid increases and the maximum error is 14%. Then, the vortex measurement repeatability is less than 1% within liquid holdups 0.1%, in this condition vortex street is steady. By analyzing the measurement uncertainties, it draws the conclusion that the measurement dispersion of vortex sensor is the main impact.2. Using wavelet analysis, characteristic parameters associated with the percentage of liquid in two-phase flow are extracted. It draws a conclusion that the standard deviation of the piezoelectric signal can reflect the percentage of liquid in gas-liquid two-phase flow.3. The gas-liquid two-phase flow around a bluff body is simulated by 3D.The error between experiment and numerical simulation is less than 7.310%, showing the consistency between experiment and numerical simulation. By analyzing the velocity distribution, the vortex shedding mechanism of gas-liquid two-phase flow is studied. Velocity distribution and static pressure distribution of different percentage of liquid are compared to study the relationships between vortex shedding and the liquid.4. By analyzing spectrum and static pressure field in different locations of signal detection, it draws a conclusion that the signal at the point 1D after the bluff body is more exact and ample than other points. |
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