virtaussuuttimen

A virtaussuutin, or flow nozzle, is a flow meter that measures the flow rate of a fluid by introducing a restriction in the flow path. This restriction causes a drop in pressure across the nozzle, and the magnitude of this pressure drop is related to the flow rate. Virtaussuuttimet are characterized by a contoured inlet and a cylindrical throat. The shape of the inlet is designed to create a smooth acceleration of the fluid into the throat, minimizing turbulence.

The principle of operation for a virtaussuutin is based on Bernoulli's principle, which states that for an inviscid flow, an increase in the speed of the fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy. As the fluid passes through the restricted throat of the nozzle, its velocity increases, and consequently, its pressure decreases. By measuring the pressure difference between the upstream section and the throat, the flow rate can be calculated using specific equations that take into account the fluid's density, viscosity, and the geometry of the nozzle.

Virtaussuuttimet are often used in applications where high accuracy is required and where the fluid might contain some solids. They are known for their relatively low permanent pressure loss compared to other types of orifice-based flow meters. The design of the nozzle is crucial for accurate measurement, and various standardized designs exist for different applications and fluid types. They are constructed from materials resistant to the fluid being measured and the operating conditions.