Numerical investigation of dynamic effects on unsteady flow measurements using a two-dimensional probe

The dynamic effects in measurements of unsteady flow when using a probe with quasi-steady calibration curves has been investigated in this paper by numerical simulation of the compressible flow around a fixed two-dimensional 3-hole probe. The unsteady velocity and pressure distributions as well as the hole-pressures are calculated for high frequency flow variations. The measurement errors caused by the dynamic effects indicate that considerable measurement errors may occur for high frequency flow fluctuation e. g. 2000 Hz especially when the flow around the probe head approaches separation. This work shows how numerical simulation can be used to investigate and correct for the dynamic effects.