PERFORMANCE OF SECOND CLOSURE TURBULENCE MODELS FOR STRATIFIED OPEN CHANNEL FLOW

Large eddy simulation of stably stratified open channel flow

Second-order closure in stratified turbulence: simulations and modeling of bulk and entrainment regions.

The parametrization of small-scale turbulent fluctuations in convective systems and in the presence of strong stratification is a key issue for many applied problems in oceanography, atmospheric science, and planetology. In the presence of stratification, one needs to cope with bulk turbulent fluctuations and with inversion regions, where temperature, density, or both develop highly nonlinear m...

A study of turbulence in open channel flow

Three series of experiments were conducted to study the effect of Reynolds number, near-wall perturbation and background turbulence on the characteristics of smooth open channel flows. Measurements were carried out using a laser Doppler anemometer. The variables of interest include the mean velocity, the turbulence intensity, probability density distribution and Gram-Charlier series coefficient...

Time scales of stratified turbulent flows and relations between second- order closure parameters and flow numbers

The description of turbulent mixing and chemical reactions by Lagrangian probability density function methods offers some significant advantages over other methods, mainly due to the simulation of mixing processes and the exact treatment of chemical transformations. A key problem of such methods is the information on the time scales of processes, because they determine the dynamics and intensit...

2DV Nonlinear k-ε Turbulence Modeling of Stratified Flows

The commonly used linear k-ε turbulence model is shown to be incapable of accurate prediction of turbulent flows, where non-isotropy is dominant. Two examples of non-isotropic flows, which have a wide range of applications in marine waters, are saline water flow and the stratified flows due to temperature gradients. These relate to stratification and consequently, variation of density through...