The behavior of subgrid-scale models near the turbulent/nonturbulent interface in jets

The behavior of subgrid-scale models near the turbulent/nonturbulent interface in jets is analyzed by using direct numerical simulation and large-eddy simulation (LES). The subgrid scales of motion near this region are far from equilibrium and contain an important fraction of the total kinetic energy. The Smagorinsky constant CS needs to be corrected near the jet edge and the method used to obtain the dynamic Smagorinsky constant CD is not able to cope with the intermittent nature of this region. A priori tests and LES show that near the jet edge the Smagorinsky model is superior both to the dynamic Smagorinsky and to the gradient models.