rheology of polymeric and complex nanostructured fluids
DESCRIPTION
Rheology of Polymeric and Complex Nanostructured Fluids. Investigator: Ludwig C. Nitsche , Chemical Engineering Department Collaborator: Lewis E. Wedgewood, Chemical Engineering Department. - PowerPoint PPT PresentationTRANSCRIPT
Problem Statement and Motivation
Key Achievements and Future GoalsTechnical Approach
Rheology of Polymeric and Complex Nanostructured FluidsInvestigator: Ludwig C. Nitsche, Chemical Engineering Department
Collaborator: Lewis E. Wedgewood, Chemical Engineering Department
• Derive macroscopic constitutive laws from stylized molecular models of polymers and complex fluid substructure in dilute solution.
• Obtain probability density functions describing external (translational) and internal (conformational) degrees of freedom of suspended bead-spring entities.
• Manipulate complex fluids with flow geometry and external fields.
• Developed model of cross-stream migration of polymers in flows with gradients in shear.
• The first asymptotic PDF for the classic problem of FENE dumbbells stretching in elongational flows.
• Rigorous basis for the recent “L-closure”, and analytical explanation for the numerically observed collapse of transient stress-birefringence curves for different polymer lengths.
• Numerical simulations by atomistic smoothed particle hydrodynamics (ASPH).
• “Smart swarms” of particles solve the Smoluchowski equation for translational and conformational motions of dumbbell models of polymers in dilute solution.
• Asymptotic theory (singular perturbations and multiple scales) consolidates numerics and extracts formulas for probability density profiles, scaling laws and rheological constitutive equations.
Numerical versus asymptotic PDF’s for a linear-locked dumbbell
Closure relations for the conformatioally averaged Smoluchowski equation