Direct simulation of turbulent mixing layers with a pseudospectral method.

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...

Effect of Merging Angle on Turbulent Mixing Layers

Direct numerical simulation of separating turbulent boundary layers

Direct numerical simulation of two turbulent boundary layer flows has been performed. The boundary layers are both subject to a strong adverse pressure gradient. In one case a separation bubble is created while in the other the boundary layer is everywhere attached. The data from the simulations are used to investigate scaling laws near the wall, a crucial concept in turbulence models. Theoreti...

Buoyant turbulent mixing in shear layers

Buoyancy effects in unstably stratified mixing layers express themselves through gravity currents of heavy fluid which propagate in an ambient lighter fluid. These currents are encountered in numerous geophysical flows, industrial safety and environmental protection issues [1] . During transition to turbulence a strong distortion of the separating interface between regions containing ‘heavy’ or...

Investigation of Turbulent Entrainment-Mixing Processes with a New Particle-Resolved Direct Numerical Simulation Model

13 A new particle-resolved three dimensional direct numerical simulation (DNS) model is 14 developed that combines Lagrangian droplet tracking with the Eulerian field representa15 tion of turbulence near the Kolmogorov microscale. Six numerical experiments are per16 formed to investigate the processes of entrainment of clear air and subsequent mixing with 17 cloudy air and their interactions wi...