caa a22 4500 606197931 CHVBK 20210128100931.0 cr unu---uuuuu 210128e20150301xx s 000 0 eng 10.1007/s00348-015-1920-z doi (NATIONALLICENCE)springer-10.1007/s00348-015-1920-z PIV measurements of flow around an arbitrarily moving free surface [Elektronische Daten] [Jinsoo Park, Sunghyuk Im, Hyung Sung, Jun Park] We present an image preprocessing method for particle image velocimetry (PIV) measurements of flow around an arbitrarily moving free surface. When performing PIV measurements of free surface flows, the interrogation windows neighboring the free surface are vulnerable to a lack, or even an absence, of seeding particles, which induces less reliable measurements of the velocity field. In addition, direct measurements of the free surface velocity using PIV have been challenging due to the intermittent appearance of the arbitrarily moving free surface. To address the aforementioned limitations, the PIV images with a curvilinear free surface can be treated to be suitable for a structured interrogation window arrangement in a Cartesian grid. The proposed image preprocessing method is comprised of a free surface detection method and an image transform process. The free surface position was identified using a free surface detection method based on multiple textons. The detected free surface points were used to transform PIV images of a curvilinear free surface into images with a straightened free surface using a cubic Hermite spline interpolation scheme. After the image preprocessing, PIV algorithms can be applied to the treated PIV images. The fluid-only region velocities were measured using standard PIV method with window deformation, and the free surface velocities were resolved using PIV/interface gradiometry method. The velocity field in the original PIV images was constructed by inverse transforming that in the transformed images. The accuracy of the proposed method was quantitatively evaluated with two sets of synthetic PIV images, and its applicability was examined by applying the present method to free surface flow images, specifically sloshing flow images. Springer-Verlag Berlin Heidelberg, 2015 Park Jinsoo Department of Mechanical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, 305-701, Daejeon, Korea aut Im Sunghyuk Department of Mechanical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, 305-701, Daejeon, Korea aut Sung Hyung Department of Mechanical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, 305-701, Daejeon, Korea aut Park Jun Department of Mechanical Engineering, Halla University, 28 Halladae-gil, Heungeop-myeon, 220-712, Wonju, Gangwon-Do, Korea aut Experiments in Fluids Springer Berlin Heidelberg 56/3(2015-03-01), 1-16 0723-4864 56:3<1 2015 56 348 https://doi.org/10.1007/s00348-015-1920-z 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/s00348-015-1920-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Park Jinsoo Department of Mechanical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, 305-701, Daejeon, Korea aut NATIONALLICENCE 700 1- Im Sunghyuk Department of Mechanical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, 305-701, Daejeon, Korea aut NATIONALLICENCE 700 1- Sung Hyung Department of Mechanical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, 305-701, Daejeon, Korea aut NATIONALLICENCE 700 1- Park Jun Department of Mechanical Engineering, Halla University, 28 Halladae-gil, Heungeop-myeon, 220-712, Wonju, Gangwon-Do, Korea aut NATIONALLICENCE 773 0- Experiments in Fluids Springer Berlin Heidelberg 56/3(2015-03-01), 1-16 0723-4864 56:3<1 2015 56 348