Summary:
- The article investigates the instantaneous structure of a turbulent wall-bounded flow influenced by free-stream turbulence and its streamwise evolution.
- The study uses high-resolution particle image velocimetry (PIV) measurements to analyze the flow characteristics, including the turbulence intensity, Reynolds stresses, and coherent structures.
- The findings reveal that the free-stream turbulence significantly alters the near-wall flow structure, leading to enhanced turbulence production and altered momentum transport mechanisms compared to a canonical turbulent boundary layer.