The Pitot-tube is used to measure Velocity at a point

The Pitot-tube is a device used to measure the velocity of a fluid at a specific point. It is commonly used in various industries, including aviation, hydraulics, and fluid dynamics research. The Pitot-tube was named after the French engineer Henri Pitot, who invented it in the early 18th century.

Working Principle:
The Pitot-tube works on the principle of Bernoulli's equation, which states that the total energy of a fluid flowing through a pipe is constant. It consists of a tube with two openings - one facing the direction of the fluid flow and the other perpendicular to it. The opening facing the fluid flow is called the "Pitot" opening, and the perpendicular opening is called the "static" opening.

When the Pitot-tube is inserted into a fluid flow, the fluid enters the Pitot opening and creates a pressure difference between the Pitot and static openings. This pressure difference is directly proportional to the velocity of the fluid at that specific point.

Measurement of Velocity:
To measure the velocity at a point using the Pitot-tube, the pressure difference between the Pitot and static openings is measured. This can be done using a pressure gauge or a pressure transducer connected to the tube. The pressure difference is then used to calculate the velocity using Bernoulli's equation.

Advantages of Pitot-tube:
- Non-intrusive: The Pitot-tube does not require any modification or interruption of the fluid flow, making it a non-intrusive measurement device.
- Simple and inexpensive: The design of the Pitot-tube is relatively simple and cost-effective compared to other velocity measurement devices.
- Suitable for various fluids: The Pitot-tube can be used to measure the velocity of different fluids, including gases and liquids.

Limitations of Pitot-tube:
- Positioning: The accuracy of the Pitot-tube measurement depends on its correct positioning in the fluid flow. Improper positioning can lead to inaccurate results.
- Flow disturbances: The presence of flow disturbances, such as turbulence or eddies, can affect the accuracy of the Pitot-tube measurement.
- Single point measurement: The Pitot-tube provides the velocity measurement at a specific point, but it does not provide information about the velocity distribution across the flow.

Overall, the Pitot-tube is a widely used and reliable device for measuring the velocity of a fluid at a specific point. Its simplicity, cost-effectiveness, and versatility make it a popular choice in various industries.