Viscous flows through configurations fabricated from soft materials exert stresses at the solid-liquid interface, leading to a coupling between the flow field and the elastic deformation. The resulting fluid-structure interaction affects the relationship between the pressure drop and the flow rate.

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We study how non-Newtonian fluids, which exhibit complex rheological behavior such as shear thinning and viscoelasticity, interact with soft, deformable configurations and determine the flow rate-pressure drop relation. The interplay between complex fluid rheology and wall compliance gives rise to unique coupling, including flow‑induced deformation, which is not well understood compared to Newtonian flows, even at low Reynolds numbers.

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Selected publications

Boyko E. and Christov I. C., (2023), "Non-Newtonian fluid-structure interaction: Flow of a viscoelastic Oldroyd-B fluid in a deformable channel", Journal of Non-Newtonian Fluid Mechanics.

Chun S., Boyko E., Christov I. C., and Feng J., (2024), "Flow rate-pressure drop relations for shear-thinning fluids in deformable configurations: theory and experiments", Physical Review Fluids.

Boyko E., (2025), "Interplay between complex fluid rheology and wall compliance in the flow resistance of deformable axisymmetric configurations", Journal of Non-Newtonian Fluid Mechanics.