Evolution and Features of Dust Devil?Like Vortices in Turbulent Rayleigh?Bénard Convection—A Numerical Study Using Direct Numerical Simulation

Direct Numerical Simulation of vortices

Direct numerical simulation of turbulent mixing.

The results of three-dimensional numerical simulations of turbulent flows obtained by various authors are reviewed. The paper considers the turbulent mixing (TM) process caused by the development of the main types of instabilities: those due to gravitation (with either a fixed or an alternating-sign acceleration), shift and shock waves. The problem of a buoyant jet is described as an example of...

Direct Numerical Simulation of Turbulent Flows Using Spectral Method

Direct numerical simulation (DNS) is the most accurate method of solving turbulence in fluids. In DNS the Navier-Stokes equations are solved on a fine mesh to resolve all the spatial and temporal scales present in the flow. In order to ensure high accuracy of the discrete solution, schemes with low numerical errors are necessary. Spectral methods with their low dissipation and dispersion errors...

Overview of Direct Numerical Simulation of Particle Entrainment in Turbulent Flows

An overview of removal and re-entrainment of particles in turbulent flows is presented. The procedure for the direct numerical simulation (DNS) of the Navier-Stokes equation via a pseudospectral method for simulating the instantaneous fluid velocity field is described. Particle removal mechanisms in turbulent flows in a duct are examined and effects of the near-wall coherent eddies on the parti...

Direct Numerical Simulation of Sprays: Turbulent Dispersion, Evaporation and Combustion

Numerical procedures to describe the dispersion, evaporation and combustion of a polydisperse liquid fuel in a turbulent oxidizer are presented. Direct Numerical Simulation (DNS) allows one to describe accurately the evolution of the fully compressible gas-phase coupled with a Lagrangian description in order to describe two-phase flows. Standard coupling is used for the Eulerian/Lagrangian syst...