Study on the two-way coupling turbulent model and rheological properties for fiber suspension in the contraction

A two-way coupling turbulent model is derived to understand and predict the interaction between the additive and the carrier flow field. Due to the anisotropic characteristics of the turbulence structure in the contraction, the Reynolds stress mode (RSM) is adopted as the fundamental governing equations. The additional stress item arising from fibers employs the Batchelor's constitutive equation for the dilute and semi dilute suspension and its divergence can have the forms of the additional diffusion term and the additional viscous dissipation term by derivation. Fiber orientation probability distribution is calculated by the Reynolds averaged Fokker-Plank equation. Based on the model above, the influences of fibers concentration on fiber orientation distribution and rheological properties for the suspension in the contraction are discussed by numerical simulation.