Pitot tube
From Free net encyclopedia
A Pitot tube is a measuring instrument used to measure fluid flow, 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 instrument consists of two coaxial tubes: the interior tube is open to the flow (i.e. perpendicular), while the exterior tube is open at ninety degrees to the flow (i.e. parallel). A manometer can be used to measure the difference between these two pressures and using Bernoulli's equation the flow rate of the fluid can be calculated.
The exterior tube, with an opening parallel to the flow, will register the Static pressure. The interior tube, with an opening perpendicular to the flow, will register the Stagnation pressure or otherwise called Total Pressure. Stagnation pressure is made up of Static Pressure plus Dynamic Pressure or also called Velocity Pressure (caused by the force of the fluid flowing into the tube interior). By measuring the pressure difference between the Static Pressure (exterior tube) and the Stagnation pressure (interior tube) allows the velocity of the fluid flow to be determined.
Modern aircraft measure the static pressure at the static ports along the fuselage sides.
See also
- Airspeed indicator
- Ventilation engineering
- Flow measurement
- Pitot-static system
- Calibrated airspeed
- True airspeed
- Position error
- Mach numberfr:Tube de Pitot
pt:Tubo de Pitot he:צינור פיטו it:Tubo di Pitot nl:Pitotbuis de:Pitotrohr ja:ピトー管 sl:Pitot-Prandtlova cev