Seven-hole cone probes for high angle flow measurement Theory and calibration
A non-nulling seven-hole conical pressure probe capable of measuring flow conditions at angles up to 75 deg relative to its axis is described. The theoretical rationale of the seven-hole probe is developed and the calibration procedure outlined. Three-variable third-order polynomial functions are used to represent local values of relative flow angles, total pressure, and total minus static pressure. These flow properties are determined explicitly from measured probe pressures. Flow angles are determined within 2.5 deg and Mach number within 0.05 with 95% certainty. The probe can be used in subsonic compressible and incompressible flows.