Boundary Layer Ingestion (BLI) fans demonstrate significant potential for reducing fuel consumption in aircraft propulsion. However, BLI introduces an augmented and uneven turbulence intensity profile at the engine inlet, a factor that can significantly influence turbomachinery performance. This paper aims to analyze the turbulence field within a low-speed fan test rig replicating BLI conditions. Inflow distortion was induced using a variable porosity screen, and turbulence intensity was measured using a hot-wire anemometer mounted on an automated traverse system. The paper presents experimental results obtained at various cross-sections of the rig — upstream, downstream, and between the rotor and the stator. Diverse data processing techniques were employed to derive average and instantaneous turbulence intensity values. These measured values were incorporated as inlet boundary conditions in Computational Fluid Dynamics (CFD) simulations. The CFD analysis complements the experimental findings, providing insights into the physics of how the distorted turbulence field evolves when passing through the single-stage fan. A comparison with experimental data also highlights limitations in the unsteady Reynolds-Averaged Navier-Stokes (RANS) model used. The results suggest that, in the presented test rig, changes in the loading of individual blades exert a more significant influence on turbulence field distortion downstream of the stage than the non-uniformity of inlet turbulent quantities. The average measured turbulence intensity between the rotor and the stator was 5.2%. Behind the stage, this value increased to 9.8% due to non-axisymmetric turbulence sources related to BLI in the stator row.