Reynolds-Averaged Simulation on Turbulent Drag-Reducing Flows of Viscoelastic Fluid Based on User-Defined Function in FLUENT Package

A new numerical simulation methodology for turbulent flows of viscoelastic fluid was developed for engineering application purpose based on commercial computational fluid dynamics code FLUENT package. An in-house subroutine was established and embedded into FLUENT code through userdefined function functionalization. In order to benchmark this methodology, numerical simulations on turbulent channel flows of viscoelastic fluid are conducted under different cases with drag reduction rates varied from low level to high level. FENE-P (finitely extensive nonlinear elastic-Peterlin) constitutive model is used to describe the viscoelastic effect of viscoelastic fluid flow. The turbulent model is developed in the framework of $k–ε–ν′2¯–f$ model, for which the elliptic relaxation model is modified to account for the Reynolds stress equilibrium established by the presence of elasticity in the fluid. The numerical simulation results, including velocity profiles, turbulent flow characteristics, elastic stress and conformation field, show good agreements with published DNS results, which validates the newly established method on turbulent flows of viscoelastic fluid based on FLUENT software platform for engineering applications.