Difference between Spiral Flow Meter and Vortex Street Vortex Flow Meter

『Vortex flowmeter』Related information(flow rotameter|digital flow meter|balo meter|hydraulic flow meter|volumetric meter|positive displacement meter|pitot tube flow meter|displacement meter|cfm meter|variable area flow meter|inline flow meter|differential pressure flow meter|calibrated flow meter|velocity meter|paddle wheel flow meter|oval gear flow meter|anemometer hvac|multiphase flow meter|doppler flow meter|thorpe tube flowmeter|heat flow meter)

1. Uncertainty of the vortex flowmeter

The uncertainty of the vortex flowmeter in the vortex bundle should be analyzed separately according to its classification (Class A/B), and the core influencing factors include measurement repeatability, standard device error, etc. 1. Uncertainty analysis methods for two types of vortex flowmeters: Type A flowmeter: using the instrument K coefficient to calculate the indication error, uncertainty analysis focuses on the stability of the K coefficient and the repeatability of the flow point measurement. ② B-class flowmeter: cumulative flow is used to calculate indication error, and uncertainty needs to be introduced as variables, including measurement error and pulse counting stability.

2. The main influencing factors of uncertainty need to be considered for all types of vortex flowmeters: • Flow meter repeatability: the degree of dispersion of continuous measurement data • Standard device error: such as the accuracy level of gas flow accompanying the standard device • Medium state fluctuation: density deviation caused by temperature and pressure changes. 3 In practical applications, it is recommended to prioritize using the real flow calibration method to obtain the correction parameters for specific models when the measurement accuracy requirement is higher than level 1.0. If theoretical estimation is required, component synthesis calculation can be carried out based on the mathematical model in JJG 1121-2015 "Verification Regulations for Spiral Vortex Flowmeters".

2. The difference between rotary vortex flowmeter and vortex street vortex flowmeter

Although these two types of flowmeters use the principle of fluid oscillation, they each use two comple

tely different working principles.

. A flowmeter using the principle of Karman vortex: When a fluid passes through a cylindrical object, vortices are generated on both sides of the object facing away from the fluid. When one side of the vortex develops, it suppresses the vortex on the other side. When one side of the vortex develops to a certain extent, it will detach from the cylindrical object and leave with the fluid, generating a new vortex in situ. At the same time, the vortex on the other side develops due to the loss of suppression, suppressing the newly formed vortex. The above process occurs alternately on both sides of the cylindrical object, and the frequency of occurrence is related to the flow velocity of the fluid. By detecting this frequency, the flow velocity can be obtained, and the flow rate value can be obtained. Due to the alternating release of vortices arranged like objects on both sides of a road in the fluid behind, this phenomenon is also known as vortex street. A flowmeter that works based on this principle is called a vortex flowmeter or a Kalman vortex flowmeter. A flowmeter utilizing the principle of spiral vortex: a set of twisted blades are installed in the pipeline to form a vortex generator, which rotates the fluid as it passes through, forming a vortex near the centerline of the pipeline. The center of this vortex rotates around the centerline of the pipeline while expanding its rotation radius with the fluid, causing the center of the vortex to form a spiral motion similar to a conical spiral. At this point, for a point on the pipe wall behind the vortex generator, the fluid velocity passing through will undergo a periodic change, and its frequency is related to the fluid velocity. D

Difference between Spiral Flow Meter and Vortex Street Vortex Flow Meter

1. Uncertainty of the vortex flowmeter

2. The difference between rotary vortex flowmeter and vortex street vortex flowmeter

『SILVER Official Website SERVICE』