Paper Number
FI23                         My Program 

Session
Flow-Induced Instabilities and Non-Newtonian Fluids

Title
Fiber suspension flow with wall-slip in hyperbolic symmetric geometries

Presentation Date and Time
October 21, 2025 (Tuesday) 1:50

Track / Room
Track 7 / Sweeney Ballroom D

Authors (Click on name to view author profile)

  1. Housiadas, Kostas D. (University of the Aegean, Mathematics)
  2. Beris, Antony N. (Univeristy of Delaware, Chemical and Biomolecular Engineering)
  3. Advani, Suresh G. (Univeristy of Delaware, Mechanical Engineering)

Author and Affiliation Lines (in printed abstract book)
Kostas D. Housiadas1, Antony N. Beris2 and Suresh G. Advani3
1Mathematics, University of the Aegean, Karlovassi, Samos 83200, Greece; 2Chemical and Biomolecular Engineering, Univeristy of Delaware, Newark, DE 19716; 3Mechanical Engineering, Univeristy of Delaware, Newark, DE 19716

Speaker / Presenter 
Housiadas, Kostas D.

Keywords
theoretical methods; computational methods; additve manufacturing; suspensions

Text of Abstract
We investigate the steady flow of a semi-dilute fiber suspension in symmetric hyperbolic channels and axisymmetric cylindrical pipes with wall slip. The rheology of the matrix fluid is defined solely by a Newtonian matrix fluid with a fixed velocity profile to evaluate the fiber orientation. We use the most accurate velocity profile according to the high-order lubrication theory derived by Sialmas & Housiadas (2024) by considering Navier’s linear slip along the wall(s). The flow exhibits purely extensional characteristics in the midplane, whereas slip along walls diminishes its purely shear characteristics along the wall(s). We use the Advani & Tucker (1987) model to evaluate the spatial evolution of the second order orientation tensor, whereas the 4th-order orientation tensor which appears in the equation is approximated with a hybrid closure (Advani & Tucker 1987). The final equations for the orientation tensor are solved numerically using finite difference and spectral methods developed by Housiadas et al. (2025). We conducted a parametric study to investigate the effects of the channel's aspect ratio, the contraction ratio, the interaction coefficient, and the slip coefficient. The results show a reorientation of the fiber alignment from their initial state to a more aligned configuration at the channel exit. This alignment becomes more pronounced near the midplane, due to the purely extensional nature of the flow in that region.