The Effect of Mach Number, Incidence and Hole Position on the Static Pressure Measured by a Square Ended Probe

Static probes, although widely used in supersonic tunnels and in flight, have not formed the basis for many reports on their design and behaviour at high Mach number. It is known, however, that the flow over the nose of the probe causes pressure variations such that it is some distance along the probe before the static pressure is equal to free stream static pressure. The NPL, in a series of tests at M = 1.6 showed that the pressure measured at a point situated less than 10 calibres (probe diameters) downstream of the beginning of the parallel portion of the probe was dependent on the shape of the nose.