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Demystifying the Working Principle of Vortex Flow Meters

1 December 2023

In the world of industrial instrumentation, precision and accuracy are paramount. Vortex flow meters are a vital component of this ecosystem, offering a reliable and cost-effective means of measuring the flow rate of various fluids. These devices employ a fascinating principle of fluid dynamics to provide accurate measurements. In this blog, we’ll dive deep into the working principle of vortex flow meters and explore how they function to ensure accurate flow rate measurements.

At the heart of vortex flow meters lies the principle of vortex shedding. This phenomenon occurs when a fluid, such as a gas or liquid, flows past a bluff body, creating alternating vortices in its wake. In the case of vortex flow meters, this bluff body is typically a slender, streamlined structure known as a “shedder bar” or “vortex generator.”


How Vortex Flow Meters Work

The working principle of vortex flow meters can be broken down into a few key steps:

Fluid Flow: When a fluid, be it a gas or liquid, passes through a pipeline, it encounters the shedder bar. The fluid flows around the shedder bar, and as it separates from the bar’s surface, it creates alternating vortices.

Vortex Shedding: As the fluid flows past the shedder bar, vortices form in a regular, alternating pattern. These vortices have a specific frequency that depends on factors like fluid density, viscosity, and the size and shape of the shedder bar.

Pressure Fluctuations: The vortices induce pressure fluctuations in the fluid. These fluctuations can be detected using a sensor mounted near the shedder bar. The sensor typically measures the variations in pressure or force exerted on it by the vortices.

Signal Processing: The sensor converts the pressure fluctuations into an electrical signal. This signal is then processed and analysed by the flow meter’s electronics.

Flow Rate Calculation: The vortex flow meter’s electronics use the frequency of the vortices, detected by the sensor, to calculate the flow rate. By correlating the vortex shedding frequency with the known characteristics of the fluid and the specific design of the vortex flow meter, it can accurately determine the flow rate.

Vortex flow meters offer several advantages, which make them a popular choice in many industrial applications:

Accuracy: Vortex flow meters provide accurate measurements, especially for clean and stable fluids.

Low Maintenance: These meters have no moving parts in contact with the fluid, reducing wear and tear, and minimizing maintenance requirements.

Versatility: Vortex flow meters can be used for a wide range of fluids, from gases to liquids, and are suitable for various industries.

Cost-Effective: They are a cost-effective solution for measuring flow rates in many applications.


Vortex flow meters, based on the principle of vortex shedding, are versatile and reliable instruments for measuring fluid flow rates in a wide range of industrial processes. By exploiting the regular formation of vortices downstream of a shedder bar, these devices provide accurate and consistent measurements. Their ability to handle various fluids, low maintenance requirements, and cost-effectiveness make them a valuable tool for engineers and technicians in many industries. Understanding the working principle of vortex flow meters is crucial for ensuring their proper selection and operation in industrial applications.