In this paper, a numerical investigation of the effect of a miniaturized five-hole probe downstream of a transonic low-pressure turbine vane row is presented. Firstly, a numerical calibration of the probe was performed. The effect of the probe on the flow-field throughout the vane segments was then evaluated by performing a comparison between a setup with vanes-only (no probe) and with vanes and probe. To assess the accuracy of the quantities ‘measured’ by the probe, the probe-determined flow-field was compared to the flow-field of the vanes-only setup. A non-negligible modification of the probe-determined local distributions of Mach number, yaw and pitch angle is revealed with respect to the undisturbed flow. A correction is used to account for the effects of the non-uniformity of the flow and its impact is evaluated on 2D and 3D flow regions. A significative effect of the correction was found on the probe-determined yaw angle, in which the difference from the vanes-only data was reduced to below 1 degree, except near the endwalls where larger discrepancies remain due to probe-endwall interactions. A shortfall of the correction was instead observed on the probe-determined Mach numbers. Finally, the pitch-wise averaged quantities were evaluated. It was observed that the highest differences between probe-determined and undisturbed data occur where radial gradients of total pressure are stronger and that the correction had almost negligible impact on the pitch-wise averaged quantities.

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