Robust procedure for multi-hole probe data processing

Multi-hole probes represent a durable and economic option to measure flow angles, total and static pressures in complex flow environments. The pressure readings are converted into flow direction using pressure calibration maps. However, depending on the geometry or manufacturing imperfections, conventional flow angle data reduction methods cannot guarantee uniqueness in the solution. This paper presents and demonstrates a novel data processing approach in a turbine measurement campaign. The new technique relies on a database of non-dimensional pressures (one per hole) instead of differential pressure levels. In addition, the new approach allows computing flow direction when a hole is blocked during the test campaign.

► This study proposes a robust post-processing procedure for directional probe.
► The technique correlates the measured pressures to a calibration pressure database.
► The flow angles are found by minimizing the distance to the pressures.
► The method recognizes and corrects a pressure port failure.
► The method is demonstrated in a wind tunnel test.