Model Pressure Measurement

Pressure measurements are obtained from pressure “tappings” on the model surface which are pneumatically linked to electronically scanned pressure (ESP) modules installed inside the model. Pressures are calculated from the signals sent from the ESP modules using coefficients obtained during in-test calibrations of the modules.

ARA has a world-leading capability in the number of pressures that it can install and test on a model – we can install and measure nine hundred and seventy six pressure tappings on sixteen ESP modules.

The photograph shows pressure tappings over a wing leading edge.

Technical Information

The class of module most commonly used in ARA models is the ±1034mB (15psi) ESP module which has 64 ports and an accuracy of ±1mB; this corresponds to a pressure coefficient accuracy of ∆Cp = ±0.002 at Mach 0.8.

The accuracy value of ±1mB includes the complete pressure measuring equipment system which comprises the ESP module, pneumatic tubing, signal wiring, signal processing equipment and the data recording device.

Where very high accuracy pressure measurements are required (but with a smaller pressure range), ±345mB (5psi) ESP modules are used instead.

The photograph shows a typical 64 port ESP module.

Latest Technology 

The very latest flow measurement techniques, such as Pressure Sensitive Paint, are in use at ARA.