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

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 $R{e}_{\tau }\approx 5100$, 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.