Theoretical derivation and calibration technique of a hemispherical-tipped, five-hole probe

A technique is presented for the calibration of a hemispherical tipped 0.125 inch diameter 5-hole probe. The derivation of equations from the potential flow over a sphere relating the flow angle and velocity to pressure differentials measured by the probe is presented. The technique for acquiring the calibration data and the technique used to calculate the calibration coefficients are presented. The accuracy of the probe in both the uniform calibration flow field and the nonuniform flow field over a 75 degree swept delta wing is discussed.