Pitot tube
Encyclopedia : P : PI : PIT : Pitot tube
A Pitot (pronounced pē-tó) tube is a measuring instrument used to measure fluid flow velocity, and more specifically, used to determine airspeed on aircraft. The Pitot tube is named after its inventor, Henri Pitot, and was modified to its modern form by Henry Darcy.
The basic pitot tube simply consists of a tube pointing directly into the fluid flow. As this tube contains air, a pressure can be measured as the moving air is brought to rest. This pressure is the stagnation pressure of the air, also known as the total pressure, or sometimes (particularly in aviation circles) the pitot pressure.
The measured stagnation pressure cannot of itself be used to determine the airspeed. However, since Bernoulli's equation states that
- :stagnation pressure = static pressure + dynamic pressure
Instead of static ports, a pitot-static tube may be employed, which has a second tube coaxial with the pitot tube with holes on the sides, outside the direct airflow, to measure the static pressure.
Pitot tubes on aircraft commonly have heating elements to prevent the tube from becoming clogged with ice.
See also
- Airspeed indicator
- Ventilation engineering
- Flow measurement
- Pitot-static system
- Calibrated airspeed
- True airspeed
- Position error
- Mach number
References
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.