To determine the inlet flow quality, a pitot rake needs to be constructed. The first image on the left shows an example of a pitot setup, with pitot tubes measuring the total pressure oriented parallel to the airstream, with wall static ports perpendicular to the flow.

Each "ring" of pitot tubes are of equal area as shown in the second image.

Using a the corresponding wall tap with the pitot measurements, an estimate of the flow velocity can be obtained using:

Dynamic Pressure = Total Pressure - Static Pressure = 1/2 x Density x Velocity^2

An example of the results from a modified scramjet are shown in the third image.

Please watch the video below which details the construction of the pitot rake.

Video showing all key steps during the construction of a pitot rake system and a time lapse of preparing for the inlet flow quality test.

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