Prandtl tube

Definition

A Prandtl tube, also known as a Pitot tube, is a device used to measure fluid flow velocity by converting the kinetic energy in a fluid flow to potential energy. It is commonly used in aerodynamics and hydrodynamics for measuring airspeed and water speed.

5 Must Know Facts For Your Next Test

1. The Prandtl tube measures the stagnation pressure and static pressure to determine the dynamic pressure of the fluid.
2. It operates based on Bernoulli's equation, which relates the pressure, velocity, and height in a fluid flow.
3. The difference between stagnation pressure and static pressure gives the dynamic pressure, which can be used to calculate the flow velocity.
4. Prandtl tubes are essential for applications involving aircraft speed measurements and industrial fluid dynamics processes.
5. Accuracy of measurements can be affected by factors such as turbulence, alignment with flow direction, and calibration.

Review Questions

• What principle does the Prandtl tube utilize to measure flow velocity?
• How does a Prandtl tube determine dynamic pressure from measured pressures?
• List two factors that might affect the accuracy of measurements taken by a Prandtl tube.

Related terms

Stagnation Pressure: The total pressure at a point in a fluid where it is brought to rest isentropically.

Static Pressure: The pressure exerted by a fluid at rest or perpendicular to its motion.

Dynamic Pressure: $q = \frac{1}{2} \rho v^2$, where $q$ represents dynamic pressure, $\rho$ is fluid density, and $v$ is flow velocity.