Turbulent Buoyant Jets in Density-Stratified Fluids

The fluid dynamics of turbulent buoyant jets in density-stratified fluids is an important class of environmental and industrial problems, including exhaust from smoke stacks, marine outfalls, hydrothermal vents, and deep-ocean oil-well accidents.   Our focus is to perform eddy-resolving simulations of turbulence under the influence of both inhomogeneous thermo-haline stratification and vertical shear found in the ocean.   An OpenFOAM application has been developed which solves the incompressible Navier-Stokes equations in Boussinesq form, transport and diffusion equations of temperature and salinity fields, a run-time selectable sea-water equation of state, and turbulence closure using both statistical (RANS) and large-eddy simulation (LES) methods.   Simulations will be conducted over a range of Reynolds and Richardson numbers to acquire data for understanding the balance of shear vs. buoyancy production, impact of stratification profiles on vertical turbulent flux and eddy structure, and general accuracy of RANS vs. LES to capture the relevant physics.   Validation will be performed by comparing simulation data to recent high-resolution particle-image velocimetry (PIV) experiments.