Incompressible Homogeneous Buoyancy-Driven Turbulence

We review recent results concerning the idealized framework of incompressible homogeneous buoyancy-driven turbulence, shedding light on the mixing process occurring in variable density fluids subjected to accelerations. Self-similar analysis, results from numerical simulations and anisotropic spectral models establish the sensitivity of the late time dynamics to the distribution of energy at large scales, to the different properties of the mixing and to the resonances inside the mixing zone when a time-varying acceleration is applied. The isotropic and anisotropic part of turbulent spectra are also investigated. Different scenarii are proposed to explain how the turbulent scales within the inertial range are altered by buoyancy forces.