Abstract
Scanning-Particle-Image-Velocimetry Technique (SPIV), introduced by Brücker (1992) and Brücker and Althaus (1992), offers the quantitative investigation of three-dimensional vortical structures in unsteady flows. On principle, this technique combines classical Particle-Image-Velocimetry (PIV) with volume scanning using a scanning light-sheet. In our previous studies, single scans obtained from photographic frame series were evaluated to show the instantaneous vortical structure of the respective flow phenomena. Here, continuous video recordings are processed to capture also the temporal information for the study of the set-up of 3D effects in the cylinder wake. The flow is continuously sampled in depth by the scanning light-sheet and in each of the parallel planes frame-to-frame cross-correlation of the video images (DPIV) is applied to obtain the 2D velocity field. Because the scanning frequency and repetition rate is high in comparison with the characteristic time-scale of the flow, the evaluation provides a complete time-record of the 3D flow during the starting process. With use of the continuity concept as described by Robinson and Rockwell (1993), we obtained in addition the out-of-plane component of the velocity in spanwise direction. This in view, the described technique enabled the reconstruction of the three-dimensional time-dependent velocity and vorticity field. The visualization of the dynamical behaviour of these quantities as, e.g. by video, gave a good impression of the spanwise flow showing the “tornado-like” suction effect of the starting vortices.
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References
Adrian RJ (1991) Particle-Imaging Techniques for experimental fluid mechanics. Ann Rev Fluid Mech 23: 261–304
Brücker Ch (1992) Dreidimensionale quantitative Vermessung des Wirbelaufplatzens mit der Particle Tracking-Velocimetry (PTV) kombiniert mit Lichtschnitt-Scanning. DGLR-report 92-07:445–454
Brücker Ch; Althaus W (1992) Study of vortex breakdown by particle tracking velocimetry (PTV). Part 1: Bubble-type vortex breakdown. Exp Fluids 13: 339–349
Brücker Ch (1991) Struktur und Entwicklung eines wandgebundenen Anfahrwirbels. Unpublished results, presented at the “Aerodynamisches Seminar”, Aerodynamic Institute of the RWTH Aachen, Germany
Brücker Ch (1994) Digital Particle Image Velocimetry (DPIV) in a scanning light-sheet: application to the 3D starting flow around a short cylinder. Proc 2 Int Conf Exp Fluid Mech 4–8 July 1994, Torino, Italy (ed. Onorato, M.): 371–380
Brücker Ch (1995) Stereoscopic DPIV in a scanning light-sheet: Technique and applications. Sent to be presented at the 6th Int Conf Laser Anemometry, August 13–18, 1995, Hilton Head Island, USA
Gad el Hak M (1988) Visualization techniques for unsteady flows: An overview. J Fluid Eng 110: 231–243
Hinsch KD (1993) The many dimensions of optical flow diagnostics. SPIE 2052: 63–78
Leweke T (1991) Axiale Strömung in schlanken Wirbeln. M. S. Thesis, RWTH Aachen, Germany
Leweke T; Swada T (1992) Structure of a starting-vortex. In: Flow Visualization VI (eds Tanida, Y; Miyashiro, H). pp 196–200, Tokyo: Springer Verlag Berlin Heidelberg
Meinhart CD; Barnhart DH; Adrain RJ (1994) An interrogation and vector validation system for holographic particle image fields. Proc 7th Int Symp Appl of Laser Techniques to Fluid Mech, Lissbon: 1.4.1–1.4.6
Meng H; Hussain F (1991) Hologaphic particle velocimetry: a 3D measurement technique for vortex interactions, coherent structures and turbulence. Fluid Dyn Res 8: 33–52
Pineau G; Texier A; Coutanceau M; Phuoc Loc (1992) Experimental and numerical visualization of the 3D flow around a short circular cylinder fitted with endplates. In: Flow Visualization VI. (eds Tanida, Y; Miyashiro, H). pp 343–347, Tokyo: Springer Verlag Berlin Heidelberg
Prasad AK; Adrian RJ (1993) Stereoscopic particle image velocimetry applied to liquid flows. Exp Fluids 15: 49–60
Robinson O; Rockwell D (1993) Construction of three-dimensional images of flow structure via particle tracking techniques. Exp Fluids 14: 257–270
Rockwell D; Magness C; Towfighi J; Akin O; Corcoran T (1993) High image-density particle image velocimetry using laser scanning techniques. Exp Fluids 14: 181–192
Sinha SK; Kuhlman PS (1992) Investigating the use of stereoscopic particle streak velocimetry for estimating the three-dimensional vorticity field. Exp Fluids 12: 337–384
Visbal MR (1993) Computational study of vortex breakdown on a pitching delta wing. AIAA Paper 93-2974
Weinstein LM; Beeler GB (1988) Flow measurements in a water tunnel using a holocinematographic velocimeter. AGARD-CP-413:16-1–16-7
Westerweel J; Nieuwstadt FTM (1991) Performance tests on 3- dimensional velocity measurements with a two-camera digital particle-image-velocimeter. Laser Anem Vol 1 ASME 1991: 349–355
Willert C; Gharib M (1991) Digital Particle Image Velocimetry. Exp Fluids 10: 181–193
Williamson CHK (1989) Oblique and parallel modes of the vortex shedding in the wake of a circular cylinder at low Reynolds numbers. J Fluid Mech 206: 579–627
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Brücker, C. Digital-Particle-Image-Velocimetry (DPIV) in a scanning light-sheet: 3D starting flow around a short cylinder. Experiments in Fluids 19, 255–263 (1995). https://doi.org/10.1007/BF00196474
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DOI: https://doi.org/10.1007/BF00196474