Numerical prediction of non-isothermal flow of nylon-6 past a cylinder between plates

Numerical simulations were undertaken for the non-isothermal creeping flow of a nylon-6 melt past a circular cylinder between plates. The fluid model used for this flow simulation is a non-isothermal White-Metzner constitutive equation, which describes the non-Newtonian behavior of nylon-6. The results were computed by an elastic-viscous split stress finite element method (EVSS-FEM), a mixed finite element method, incorporating the streamline upwind Petrov-Galerkin (SUPG) scheme. To verify the numerical algorithm, it was first applied to compute the corresponding isothermal flow of a shear-thinning solution of 5 wt% polyisobutylene in tetradecane (PIB/C14), modeled by the Phan-Thien Tanner model. The resulting velocity and stress fields were compared with known experimental data. Subsequently, both the isothermal and non-isothermal drag forces on the cylinder and the local heat transfer coefficients along the cylinder wall and channel wall were predicted. The effects of fluid elasticity, shearthinning, temperature-thinning, and heat transfer were investigated.