Venturi Tube

A Venturi tube is a device used in flight instruments to measure the airspeed of an aircraft. It is a type of flow meter that utilizes the principle of Bernoulli's equation to determine the velocity of a fluid (in this case, air) passing through a constricted section of a tube.

In the context of flight instruments, the Venturi tube is typically located in the pitot-static system of an aircraft. The pitot-static system consists of a pitot tube, which measures the dynamic pressure of the air, and a static port, which measures the static pressure of the air. The Venturi tube is connected to both the pitot tube and the static port.

As air flows through the Venturi tube, it passes through a narrow section called the throat. This constriction causes the air to speed up, resulting in a decrease in pressure according to Bernoulli's equation. By measuring the pressure difference between the pitot tube and the static port, the airspeed of the aircraft can be determined.

The Venturi tube is an essential component of the airspeed indicator, which is a flight instrument that displays the aircraft's airspeed. It is also used in other flight instruments, such as the Machmeter, which measures the aircraft's speed relative to the speed of sound.

In summary, the Venturi tube is a device used in flight instruments to measure the airspeed of an aircraft by utilizing the principle of Bernoulli's equation and the pressure difference between the pitot tube and the static port.