caa a22 4500 606198342 CHVBK 20210128100933.0 cr unu---uuuuu 210128e20150401xx s 000 0 eng 10.1007/s00348-015-1938-2 doi (NATIONALLICENCE)springer-10.1007/s00348-015-1938-2 Convergence enhancement of single-pixel PIV with symmetric double correlation [Elektronische Daten] [Francesco Avallone, Stefano Discetti, Tommaso Astarita, Gennaro Cardone] A symmetric correlation approach is proposed to improve the convergence of the single-pixel technique for particle image velocimetry (PIV). Nogueira et al. (Exp Fluids 30:309-316, 2001) introduced this method to remove a source of random errors in PIV when small interrogation windows are used; it consists in applying the cross-correlation operator by considering fixed the first exposure and moving the second one, and vice versa, and then calculating the cross-correlation map as the average of the two maps. The symmetric correlation suppresses the effects of truncation of the particles lying on the border of the interrogation windows. In this paper, the application of symmetric correlation to single-pixel PIV algorithms is reported. Since symmetric direct correlation provides a significant improvement in the cross-correlation peak shape with respect to the standard asymmetric single-pixel implementation, a faster convergence in estimating the average velocity components and turbulence statistics is achieved. An additional improvement is due to the possibly limited correlation between the background noise for the two exposures. The algorithm is tested via synthetic images with imposed constant and sinusoidal displacement and then tested with real data of a jet flow. The technique has shown that the same accuracy of the standard asymmetric approach can be achieved with 50% of the samples and that a reduction in the measurement error by 30% is obtained when using the same number of samples. Springer-Verlag Berlin Heidelberg, 2015 Avallone Francesco Department of Industrial Engineering (DII), Universitá degli Studi di Napoli Federico II, P.leTecchio 80, 80125, Naples, Italy aut Discetti Stefano Aerospace Engineering Group, Universidad Carlos III de Madrid, Av. de la Universidad 30, 28911, Leganés, Spain aut Astarita Tommaso Department of Industrial Engineering (DII), Universitá degli Studi di Napoli Federico II, P.leTecchio 80, 80125, Naples, Italy aut Cardone Gennaro Department of Industrial Engineering (DII), Universitá degli Studi di Napoli Federico II, P.leTecchio 80, 80125, Naples, Italy aut Experiments in Fluids Springer Berlin Heidelberg 56/4(2015-04-01), 1-11 0723-4864 56:4<1 2015 56 348 https://doi.org/10.1007/s00348-015-1938-2 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/s00348-015-1938-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Avallone Francesco Department of Industrial Engineering (DII), Universitá degli Studi di Napoli Federico II, P.leTecchio 80, 80125, Naples, Italy aut NATIONALLICENCE 700 1- Discetti Stefano Aerospace Engineering Group, Universidad Carlos III de Madrid, Av. de la Universidad 30, 28911, Leganés, Spain aut NATIONALLICENCE 700 1- Astarita Tommaso Department of Industrial Engineering (DII), Universitá degli Studi di Napoli Federico II, P.leTecchio 80, 80125, Naples, Italy aut NATIONALLICENCE 700 1- Cardone Gennaro Department of Industrial Engineering (DII), Universitá degli Studi di Napoli Federico II, P.leTecchio 80, 80125, Naples, Italy aut NATIONALLICENCE 773 0- Experiments in Fluids Springer Berlin Heidelberg 56/4(2015-04-01), 1-11 0723-4864 56:4<1 2015 56 348