Project Description

Viscoelastic suspensions are polymeric fluids containing particulate matter. These systems are common in our daily lives, found in foods, consumer products, and pharmaceuticals, as well as biological fluids in our body (e.g, mucous, blood, bacterial suspensions). This project investigates the motion of non-spherical particles in polymeric fluids when shear rate gradients exist (e.g., pressure driven flows). In such situations, fluid stresses cause a non-spherical particle to acquire a torque that favors specific orientations, as well as lift forces that focuses the particle to specific streamlines in the fluid. The orientation and lift forces are intimately coupled, which to this point has not been investigated but play a major role in the processing of fiber-like and disk-like dispersions in polymer melts, pastes, and coatings, as well determining the dispersion’s behavior in mixing and separation applications. The postdoc will perform theories and direct numerical simulations that quantify orientation and lift forces on non-spherical particles in channel flows and flows containing bends, understanding how fluid viscoelasticity, fluid inertia, and geometric confinement affect the final particle position and the time-scale to reach this position. Microfluidic experiments and holographic imaging will also be performed to obtain 3D position and orientation distributions at different channel locations. 

Start Date

May 2025

Post Doc Qualifications

The postdoctoral researcher should have a degree in Chemical Engineering, Mechanical Engineering, Materials Science, or equivalent. The research requires a strong background in fluid mechanics and rheology. Experience in microfluidics as well as working knowledge of computational fluid dynamics is desirable. 

Co-Advisors

1. Vivek Narsimhan, Assistant Professor of Chemical Engineering, vnarism@purdue.edu, https://engineering.purdue.edu/ChE/people/ptProfile?resource_id=169352

2. Arezoo Ardekani, Professor of Mechanical Engineering, ardekani@purdue.edu, https://engineering.purdue.edu/ME/People/ptProfile?resource_id=110641

Bibliography

1. C. Tai and V. Narsimhan. " Experimental and theoretical studies of cross-stream migration of non-spherical particles in a quadratic flow of viscoelastic fluid". Soft Matter, 18, 4613-4624, (2022). DOI: https://doi.org/10.1039/D2SM00011C

2. S. Wang, C. Tai, and V. Narsimhan. “Dynamics of spheroids in an unbound quadratic flow of a general second-order fluid". Physics of Fluids, 32, 113106, (2020). DOI: https://aip.scitation.org/doi/10.1063/5.0030517

3. Li G, McKinley GH, Ardekani AM. Dynamics of particle migration in channel flow of viscoelastic fluids. J Fluid Mech. 2015;785:486-505. doi: 10.1017/jfm.2015.619

4. Karimi A, Yazdi S, Ardekani AM. Hydrodynamic mechanisms of cell and particle trapping in microfluidics. Biomicrofluidics. 2013;7(2):021501. doi: 10.1063/1.4799787.

5. A.H. Raffiee, S. Dabiri, A.M. Ardekani, “Elasto-inertial migration of deformable capsules in a microchannel”, Biomicrofluidics, 11, 064113, 2017