Development and characterisation of a turbulent boundary layer facility at the Delft University of Technology

• The Delft University Boundary Layer Facility (DU-BLF) is a new wind tunnel testing facility that was commenced in 2024. • With a modular and optically accessible design of its test section, the DU-BLF enables studies of moderately-high Reynolds number wall-bounded turbulence studies in various configurations, e.g. , with streamwise pressure gradients and surface modifications. • An open-access dataset of a ZPG TBL, for a range of R e τ = 1 400 to 5 100 , has been described and includes spatially and temporally resolved data from HWA, PIV, PTV, and wall-pressure measurements. A new facility for studying turbulent boundary layer flows has been developed at the Delft University of Technology and is referred to as the DU-BLF: Delft University Boundary Layer Facility. Its design and boundary layer data characteristics are presented in the current work. The DU-BLF can be employed for a range of studies revolving around boundary layer flows, e.g. , covering fundamentals of boundary layer development, flow control with passive surface modifications, and control efforts with active technologies. A modular setup of the test section allows for a relatively long development length, with both physical and optical access over its complete extent. For the present characterisation, a turbulent boundary layer was developed under a zero (streamwise) pressure gradient, with the aid of a flexible ceiling. We establish the general flow characteristics, including freestream turbulence intensity levels, acoustic noise characteristics, boundary layer-integral parameters, and wall-normal profiles of the first and second-order turbulence statistics. Results are validated by employing multiple measurement techniques, namely, hot wire anemometry, particle image and tracking velocimetry, and wall-pressure measurements. Results are shown for friction Reynolds numbers up to R e τ ≈ 5 100 , and reveal that the boundary layer flow adheres to the expected behaviour of canonical wall-bounded turbulence. Data of the current turbulent boundary layer measurements are made available online .