Paper Number
PO18                         My Program 

Session
Poster Session

Title
From sedimentation to suspension: Critical strain as a predictor of particle resuspension thresholds

Presentation Date and Time
October 22, 2025 (Wednesday) 6:30

Track / Room
Poster Session / Sweeney Ballroom E+F

Authors (Click on name to view author profile)

  1. Mahmoudian, Mohammadreza (University of Illinois at Chicago, Mechanical engineering)
  2. Rogers, Simon A. (University of Illinois Urbana-Champaign, Chemical and Biomolecular Engineering)
  3. Mirbod, Parisa (University of Illinois at Chicago, Mechanical engineering)

Author and Affiliation Lines (in printed abstract book)
Mohammadreza Mahmoudian1, Simon A. Rogers2 and Parisa Mirbod1
1Mechanical engineering, University of Illinois at Chicago, Chicago, IL 60607; 2Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801

Speaker / Presenter 
Mahmoudian, Mohammadreza

Keywords
experimental methods; microscopy; particualte systems; suspensions

Text of Abstract
Resuspension of solid particles in fluids is a fundamental transport process with implications for sediment and contaminant mobilization in rivers, erosion control, biogeochemical cycling, mixing in chemical and food processing. While turbulent resuspension is well studied, far less is known about dense particle beds under oscillatory, time-dependent shear flows, where particle interactions are highly dynamic and nonlinear. Here, we investigate the resuspension of non-Brownian spherical particles in a Newtonian fluid under both steady and oscillatory shear across particle volume fractions ? = 0.30–0.55. Rheology and in situ rheo-microscopy reveal that strain, rather than shear rate, is the primary parameter governing the onset and completion of resuspension. This strain-driven transition from a quiescent sediment bed to a fully suspended state arises from enhanced particle–particle collisions and collective motion. A particle-collision-based theoretical model quantitatively predicts critical resuspension strains as a function of volume fraction, enabling the construction of universal state diagrams for both steady and oscillatory flows. These findings establish a predictive framework for controlling suspension dynamics in environmental, industrial, and biomedical systems.