Author(s): Carolina Boffo, Lucas Pereira, tiago oliveira, Ana Luiza Borges, Rafael Manica, Tiago Oliveira, Paulo Paraizo

Linked Author(s): tiago oliveira

Keywords: Turbidity currents; Medical ultrasound; Hydrodynamic visualization; Surface mapping;

Abstract: One of the great challenges in the physical modeling of turbidity currents is to acquire data with equipment that do not cause disturbance. Imaging equipment, such as video cameras, are an alternative for recording experiments without disturbances. However, for flows with high concentration, or where the material has unfavorable color (such as coal), visualization and analysis end up being impaired. An alternative for recording such flows is the application of an ultrasonic imaging equipment, which allows the acquisition of data with good quality and resolution. Experiments performed in NECOD laboratory (UFRGS - Brazil) showed that the images obtained by a medical ultrasound equipment could provide good qualitative and quantitative data. In a first application, the ultrasound images suggest that there is a relationship between the different current layers and the velocity and concentration profiles. For this study, the gray scale colors produced by the medical ultrasound equipment were used to calculate numerical values, by the Matlab tool with a new mathematical code. Such values allow obtaining spectra of density correlating them with the measured velocity (UVP) and concentration (UHCM) profiles. In a second experiment, the medical ultrasound enables to measure and map the evolution of the slope profile eroded by turbidity currents. An image sequence obtained during the experiment, registered a series of slope profiles allowed the mapping of the evolution and formation of a subaqueous canyon. The ultrasound is a good tool to acquire images from flow simulations, including for experiments produced in small scale.

DOI: https://doi.org/10.3850/38WC092019-1329

Year: 2019