Large eddy simulations of turbulent planar jets of viscoelastic fluids

Abstract

Direct numerical simulations and large-eddy simulations of turbulent planar jets are used to assess the distortion similarity (DSIM) model, recently developed by Ferreira et al. ["Large-eddy simulations of forced isotropic turbulence with viscoelastic fluids described by the finitely extensible nonlinear elastic rheological model with Peterlin's closure model," Phys. Fluids 28, 125104 (2016)] for homogeneous turbulence, in the simulation of turbulent viscoelastic planar jets. Both a priori and a posteriori tests of the DSIM model are used and show that the several assumptions used in the development of the DSIM model hold well in inhomogeneous free turbulent viscoelastic flows, e.g., (i) the scale similarity of the subgrid-scale (SGS) polymer stretching and (ii) the local equilibrium of the elastic energy production and dissipation. The DSIM model for the SGS polymer stretching term, together with the dynamic Smagorinsky model, is able to reproduce well the flow structures and the classical one-point statistics of turbulent viscoelastic planar jets. The model should be equally able to simulate other free shear flows of viscoelastic fluids, e.g., wakes and mixing layers.