Dynamic pressure

The dynamic pressure, the dynamic pressure, and corresponds to the increase of the pressure at the stagnation point of a body in flow from the static pressure of the fluid. With the aid of back pressure to the fluid velocity can be determined.

Measurement

For the measurement of the dynamic pressure, the static pressure on the pressure at the stagnation point ( total pressure) must be deducted. This can be done by a separate measurement of the static pressure followed by an arithmetical subtraction. Another possibility is to use a differential pressure sensor, in which the difference is formed in a physical manner. The sensor is supplied with hoses of local pressure at the stagnation point and in a plane perpendicular to flow.

The stagnation point, the measurement is taken, should be streamed as undisturbed as possible. Therefore, in an aircraft pitot tube is used, the opening of which extends a short distance across the bow or front of the tail. A special design in which the openings are set for the pressure measurements so that the smallest possible measurement error results in an oblique incident flow, the Prandtlsonde.

Mathematical Description

The flow velocity is, the static pressure, the density of the flowing medium. (In N / m, in kg / m³, in m / s )

The dynamic pressure and the total pressure at the stagnation point