Large Eddy Simulation of Evolution of a Passive Scalar in Plane Jet
Large-eddy simulation (LES) is performed to investigate the passive scalar development in a plane jet. This is a follow-up of our previous simulation of the jet e owe eld. The LES results are compared to both experiments and direct numerical simulation (DNS). Two subgrid models are investigated: the dynamic Smagorinsky model and the dynamic mixed model. It is found that the evolution of mean scalar and turbulent scalar intensity is well represented. Some properties of the LES models such as the evolution of the dynamic constant and the subgrid viscosity are also discussed. Proe les of higher scalar moments show non-Gaussianity near the jet boundaries that is associated with external intermittency. Finally, the probability density function (PDF) of the passive scalar computed with LES is obtained and compared with the true PDF obtained with DNS. The LES approach is found able to represent the main characteristics of the PDF including qualitative changes during its initial evolution.