Experimental study of surface buoyant jets in crossflow

Abstract

[Abstract:] The dispersion of surface jets in crossflows such as rivers or channels can cause critical environmental problems in the form of chemical or thermal pollution of these water bodies. The turbulent flow structures occurring in such crossflows play an important role in the mixing of surface jets with the surrounding water bodies. In this study, experimental measurements of the time history of the 3-D velocity field were conducted to better understand the flow structure of surface jets in crossflow conditions. Stereoscopic Particle Image Velocimetry was used to measure the instantaneous spatial and temporal velocity distribution downstream of the jet’s discharge point. In addition to the mean velocity distribution, turbulent flow characteristics such as the turbulent kinetic energy (k), turbulent kinetic energy dissipation rate (ϵ), and turbulent eddy viscosity (νt) were calculated. The formation and evolution of a vortex in the surface jet’s flow structure was detected over the measurement zone. The vortex in the surface jets in crossflow resembled to half of the vortices in a counter-rotating vortex pair (CVP) of submerged jets in crossflows. It can be inferred that the water surface performed like a plane of symmetry.