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CEMS > About > Faculty > Satish Kumar

Satish Kumar

Satish Kumar

Information

Professor, Director of Undergraduate Studies in Chemical Engineering

Phone: 612-625-2558
Email: kumar030@umn.edu


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Degrees

  • B.Ch.E., University of Minnesota, 1993
  • M.S., Ch.E., Stanford University, 1994
  • Ph.D., Ch.E., Stanford University, 1998

Research Areas

The processing of materials plays a central role in the disciplines of chemical engineering and materials science. Materials often are in a liquid or liquid-like state while being processed, and have interfaces with other media. Many such materials also contain complex structural elements like colloidal particles, polymer chains, and surfactant aggregates whose size is much larger than that of typical solvent molecules.

Our research involves integration of transport phenomena, colloid and interface science, rheology, applied and computational mathematics, and experiments to address fundamental issues motivated by problems in materials processing. These fundamental investigations are frequently inspired by industrial applications in areas such as coating and printing processes, polymer processing, nanofluidics/microfluidics, and energy. Topics of current interest include:

Dynamic wetting: Dynamic wetting is crucial to processes where liquid displaces another fluid along a solid surface, such as the deposition of a liquid coating onto a moving substrate or the displacement of oil in rock pores. Our efforts are aimed at improving fundamental understanding of dynamic wetting, and harnessing that understanding to address materials-processing-related issues such as the transfer of liquid between two separating surfaces and the entrainment of air in high-speed coating processes.

Interfacial instabilities: Instabilities at interfaces are usually undesirable in materials processing operations, but can sometimes be exploited for scientific and technological purposes (e.g., creating a topographically patterned surface). These instabilities can be driven by a variety of sources, including hydrodynamic, electrostatic, and intermolecular forces. We are interested in characterizing when and how interfacial instabilities occur, and in developing ways to control them.

Interfacial flows of suspensions: The successful large-scale manufacture of emerging products in the energy and electronics industries requires that particulate suspensions be coated and printed at high speeds with minimal defects. By combining ideas from colloidal rheology and interfacial fluid mechanics, we are examining a number of model problems in this area.

Polymer dynamics near surfaces: The behavior of polymers near surfaces plays a key role in a variety of applications including biosensors, suspension rheology, and the development of novel nanostructured materials. In many cases, the surface may be patterned chemically and/or topographically, and fluid flows and electric fields may be present. We are applying Brownian dynamics simulations to study how fluid flow, electric fields, and surface patterning can be designed to manipulate the behavior of macromolecules near surfaces. Various molecular theories are leveraged to guide the simulations and to understand the results.

Selected Publications

  • On the Mechanism of Wetting Failure during Fluid Displacement along a Moving Substrate (with E. Vandre and M. S. Carvalho), Phys. Fluids 25, 102103 (19 pages) (2013).
  • Dynamics of Polymer Adsorption from Dilute Solution in Shear Flow near a Planar Wall (with S. Dutta and K. D. Dorfman), J. Chem. Phys. 139, 174905 (8 pages) (2013).
  • Onset of Whipping in the Melt Blowing Process (with C. Chung), J. Non-Newtonian Fluid Mech. 192, 37-47 (2013).
  • Electrohydrodynamic Instabilities in Thin Viscoelastic Films--AC and DC Fields (with L. Espín and A. Corbett), J. Non-Newtonian Fluid Mech. 196, 102-111 (2013).
  • Electrohydrodynamic Effects in the Leveling of Coatings (with A. Ramkrishnan), Chem. Eng. Sci. 101, 785-799 (2013).
  • Thermally Induced Delay and Reversal of Liquid Film Dewetting on Chemically Patterned Surfaces (with S. K. Kalpathy and L. F. Francis), J. Colloid Interface Sci. 408, 212-219 (2013).
  • Worst-case Amplification of Disturbances in Inertialess Couette Flow of Viscoelastic Fluids (with B. K. Lieu and M. R. Jovanovíc), J. Fluid Mech. 723, 232-263 (2013).
  • Delaying the Onset of Dynamic Wetting Failure through Meniscus Confinement (with E. Vandre and M. S. Carvalho), J. Fluid Mech. 707, 496-520 (2012).
  • The Dynamics of Three-dimensional Liquid Bridges with Pinned and Moving Contact Lines (with S. Dodds and M. S. Carvalho), J. Fluid Mech. 707, 521-540 (2012).
  • Thin-film Models of Liquid Displacement on Chemically Patterned Surfaces for Lithographic Printing Processes (with S. K. Kalpathy and L. F. Francis), J. Colloid Interface Sci. 383, 155-166 (2012).