What is the function of a Venturi tube in a flow measurement system?

The function of a Venturi tube in a flow measurement system is to calculate flow based on differential pressure. A Venturi tube is designed with a converging section that narrows the flow of fluid and then a diverging section that allows the fluid to expand back to its original diameter. As the fluid passes through the narrower section, the velocity of the fluid increases while the pressure decreases, resulting in a drop in pressure.

This differential pressure between the wider and narrower sections of the tube is directly related to the flow rate of the fluid. According to Bernoulli's principle, the flow rate can be calculated by measuring the pressure difference and applying the appropriate equations that relate flow rate, fluid density, and pressure. Therefore, the primary function of a Venturi tube is to serve as a flow measuring device by leveraging the principles of fluid dynamics to quantify the flow rate based on the pressure differentials it generates.