Author(s): I. Fujita; T. Ando; S. Tsutsumi; H. Hara
Linked Author(s): Ichiro FUJITA
Keywords: No Keywords
Abstract: An imaging technique, the large-scale particle image velocimetry (LSPIV), has been introduced successfully to river flow measurements in the last decade. Although LSPIV requires tracers, seeding is almost impossible in actual flood conditions; therefore, surface ripple waves generated at highly turbulent condition have been utilized as representing surface flow marker. The shortcoming of LSPIV is its limited applicability of around-the-clock monitoring, because it becomes difficult to track surface ripple movements during the night or in heavy rain condition. In order to overcome these difficulties and broaden the applicability of imaging techniques, the authors have developed an alternative method, the space-time image velocimetry (STIV) for measuring streamwise velocity distributions. In the present study, the efficiency of STIV is improved successfully by applying the two-dimensional fast Fourier transform for extracting reliable flow information from space-time images.
Year: 2009