Simulation of flow of short fiber suspensions through a planar contraction

In this study, the flow of a fiber filled viscoelastic matrix through planar contractions is investigated. It was found that by adding fiber to the matrix vortex, the intensity increases. Fiber orientation along “xx” and “yy” axes was studied too. It was found that fiber orientation could be used for determining the flow regime through the contraction geometry. The rigidity condition of fibers, which needs the trace of the orientation tensor to be unity everywhere in the domain, is correct except near walls and the reentrant corner, which is slightly less than one. In these regions, the stress magnitude is higher, which results in more numerical errors, and which further leads to some error in predicting the orientation tensor. The first normal stress difference distribution along different axes was also studied in this article. It was found that increasing the volume concentration of fibers results in first normal stress difference intensification.