Gravity currents in a variable density environment: an experimental study

Abstract

Gravity currents are important in both natural contexts, such as ocean currents and avalanches, and industrial situations, such as wastewater treatment and tunnel fires. Studying these currents is critical for tackling major health and environmental issues. This research effort seeks to investigate the dynamics of gravity currents such as their movement and mixing with the environment as they flow through locations of varied densities. At LEMTA, with cutting-edge experimental facilities and novel measuring methodologies, like PIV and light attenuation technique, numerous experiments have been conducted to track the progression of gravity currents, to comprehend how these fluxes convey materials. During the experiment heavier or more dense fluid and lighter fluid in the experimental tank are separated by a lock. By employing LAT and PIV technology images have been captured during the real-time experiment. One of the most challenging parts was to extract detailed and realistic information on physical values like density, velocity that can be combined in a buoyancy flux field from the pixel information of the camera. Simultaneously capturing the event with proper measurement was significant as well. The result also shows us the lobe and cleft instability and vortices generated during the progression of the current which is important to analyze the energy transportation and behavior of the heavier fluid. These improvements have the potential to inform mitigation methods for gravity currents' effects on the environment.