11th European Conference on Turbomachinery Fluid dynamics & Thermodynamics
To continuously improve jet-engines, it is necessary to precisely predict gas turbine flow fields using computational fluid dynamics (CFD). The results of the simulations are validated with pressure probe measurements. The pressure probe is intended to determine the flow field between the blade rows but as the probe is positioned in the flow passage, it disturbs the flow field. This study investigates the influence of a multi-hole pressure probe on the flow field in a multistage axial air-turbine. To this end, probe measurements are conducted, and the experimental results are compared to the results of CFD simulations. These simulations are done with and without the probe in the flow passage to investigate the effect the probe has on the flow field numerically. The simulations with and without probe are in good agreement for flow areas with low gradients. In areas with high velocity gradients, the probe shifts the vane wake circumferentially and reduces the wake magnitude. The numerical probe measurements agree well with the experimental probe measurements especially in the wake region. Based upon these results, the differences between probe measurements and numerical results are mainly caused by the potential effect of the probe. This effect must be considered in the analysis of experimental data of multi-hole pressure probes.