caa a22 4500 606197192 CHVBK 20210128100928.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s00348-014-1892-4 doi (NATIONALLICENCE)springer-10.1007/s00348-014-1892-4 Willert Christian German Aerospace Center (DLR), Institute for Propulsion Technology, 51170, Cologne, Germany aut High-speed particle image velocimetry for the efficient measurement of turbulence statistics [Elektronische Daten] [Christian Willert] A high-frame-rate camera and a continuous-wave laser are used to capture long particle image sequences exceeding 100,000 consecutive frames at framing frequencies up to 20kHz. The electronic shutter of the high-speed CMOS camera is reduced to $$10\,\upmu$$ 10 μ s to prevent excessive particle image streaking. The combination of large image number and high frame rate is possible by limiting the field of view to a narrow strip, primarily to capture temporally resolved profiles of velocity and derived quantities, such as vorticity as well as higher order statistics. Multi-frame PIV processing algorithms are employed to improve the dynamic range of recovered PIV data. The recovered data are temporally well resolved and provide sufficient samples for statistical convergence of the fluctuating velocity components. The measurement technique is demonstrated on a spatially developing turbulent boundary layer inside a small wind tunnel with $$Re_\delta = 4{,}800,\, Re_\tau = 240$$ R e δ = 4 , 800 , R e τ = 240 and $$Re_\theta = 515$$ R e θ = 515 . The chosen magnification permits a reliable estimation of the mean velocity profile down to a few wall units and yields statistical information such as the Reynolds stress components and probability density functions. By means of single-line correlation, it is further possible to extract the near-wall velocity profile in the viscous sublayer, both time-averaged as well as instantaneous, which permits the estimation the wall shear rate $$\dot{\gamma }$$ γ ˙ and along with it the shear stress $$\tau _w$$ τ w and friction velocity $$u_\tau$$ u τ . These data are then used for the calculation of space-time correlation maps of wall shear stress and velocity. Springer-Verlag Berlin Heidelberg, 2015 Experiments in Fluids Springer Berlin Heidelberg 56/1(2015-01-01), 1-17 0723-4864 56:1<1 2015 56 348 https://doi.org/10.1007/s00348-014-1892-4 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00348-014-1892-4 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Willert Christian German Aerospace Center (DLR), Institute for Propulsion Technology, 51170, Cologne, Germany aut NATIONALLICENCE 773 0- Experiments in Fluids Springer Berlin Heidelberg 56/1(2015-01-01), 1-17 0723-4864 56:1<1 2015 56 348