Within the study of free surface flows, measurements in the vertical planes of the flow are desired. Using Particle Image Velocimetry, usually measurements are performed with the laser sheet through the bottom of the channel in order to avoid the optical perturbations on the laser light sheet, generating light scattering and measurement artefacts. There are however a number of cases where this is not possible since the transparence of the bottom cannot be ensured. In the present study we wanted to check the influence of the illumination on the velocity fields distribution, through the bottom of the channel or through the free surface, on a very simple flow on a plane plate placed on the bottom of a circular channel. We also checked the influence on using conventional silver hollow glass spheres and fluorescent particles. The results allowed us to conclude that in the cases where the study is focused on the boundary layer close to the solid surface and the observed perturbations of the free surface are not important, top illumination of the open channel might be considered as an option if perturbations of the free surface are not observed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.