An improved k-ω turbulence model for FENE-P fluids without friction velocity dependence

An improved k-ω turbulence model for viscoelastic fluids is developed to predict turbulent flows, with polymeric solutions described by the finitely extensible nonlinear elastic-Peterlin constitutive model. The k-ω model is tested against a wide range of direct numerical simulation data in fully-developed channel flow, with different rheological parameter combinations, and can predict all regimes of drag reduction (low, intermediate and high) with good performance. Closures are improved for the NLTij term, which captures the polymer extension due to turbulent fluctuations; a modified damping function, fμ, which accounts for the turbulent kinetic energy redistribution process; and the viscoelastic destruction term, Eτp. The main advantage of the current model is its ability to predict all flow features with model simplicity and without the need for friction velocity dependence, important for flows with reattachment due to their singularity caused by the stagnation points.