Dynamic Pressure

Short Name or Variable Name:

QCF, QCR (also QCFR on the C-130)

HAIS Instrument:

TABS

Description

Model:

GV: Honeywell PPT0005GXX2VB-S021; C-130: Rosemount 1221F

Measurements Provided:

Dynamic Pressure

General Description:

The dynamic pressure is the excess pressure above ambient that develops when air is compressed and adiabatically brought to rest relative to the moving aircraft. The total pressure, the sum of ambient and dynamic pressure, is normally sensed using a pitot tube, a tube pointed in the direction of the relative airflow and specially designed to be relatively insensitive to small-angle changes in the direction of the relative airflow. The difference between this measurement and the static pressure measurement (see http://www.eol.ucar.edu/instruments/ambient-static-pressure) is the measured dynamic pressure. The dynamic pressure is equal to 0.5 times the air density times the airspeed squared, so dynamic pressure can be used to determine the airspeed of the aircraft. On RAF aircraft, the measurement of dynamic pressure is made by Honeywell digital differential transducers. Because any errors affecting the measurement of static pressure also affect the difference between total and static pressure, the same corrections that are applied to static pressure (for errors in the pressure delivered by the static ports) are also applied to the dynamic pressure, with reversed sign. See the discussion of processing algorithms in the Documentation section.

Measurement Characteristics:

Calibration Methods:

RAF Calibration Cart / Traceable Pressure Standard - GV is digital so not susceptible to DSM A2D temperature variations.

Contacts

Lead Contact:

Lou Lussier

Status/Plans

Current Location:

GV/C-130

Operational Status:

requestable, ready for deployment

Data

External Deployments or Description:

This measurement is typically available on all projects.

Lifecycle

Date Acquired:

January, 2008

Serial Numbers

Property Tag and/or Serial Number:

Not Available