Development of a 17-hole omnidirectional pressure probe

A study was conducted to design and fabricate a 17-hole omnidirectional pressure probe for three-dimensional flowfield measurement. The idea was initiated from the 18-hole probe and the port arrangement was essentially same as the 18-hole one, but with one port substituted by the sting. The data reduction algorithm for the 17-hole probe was based on the algorithm of the conventional five- or seven-hole probe. A preliminary procedure divided the 17 pressure ports into different zones and discover the zone facing the flow. An interpolation procedure was applied for the specific zone to obtain flow variables. The data reduction algorithm contained two steps, such as partitioning and interpolating. The 17-hole probe differed from a conventional five- or seven-hole probe by its port count and measuring angle range. The probe was calibrated for roll angle varying from -180 to 180 degrees, and cone angle varying from 0 to 150 degrees with interval of 5 degrees, which produces a total of 2232 calibration points.