Current  research

 



Modeling, design and analysis of  PEMFC
Fuel cells are continuous batteries that run on hydrogen or conventional hydrocarbons. They produce electricity more efficiently and quietly than conventional fossil fuel burners and have high power densities (in units of W/cm3). For improved design and control of fuel cells, better understanding is necessary of  fuel cell systems and components by means of experimentally-validated accurate models of the transport phenomena, structural and thermal behavior of fuel cells. We have two and three dimensional transient and steady-state models of PEM fuel cells.

Hydrogen concentration

Oxygen concentration

 

Hydrogen (left) and Oxygen (right) mass fractions in anode (left) and cathode (right) flow channels and gas diffusion layers obtained by 3D modeling of a U-section of PEM fuel cell by COMSOL.


Projects

Publications

  1. S. Yesilyurt, "Modeling and Simulations of PEM Fuel Cesll with Poroelastic Approach for Coupled Liquid Water Transport and Deformation in the Membrane," Journal of Fuel Cell Science Technology, 7 (3), 031008-031017, 2010.
  2. J.B. Siegel, S.B. Bohac, A.G. Stefanopoulou, S. Yesilyurt, “Nitrogen front evolution in purged polymer electrolyte membrane fuel cell dead-ended anode,”J. Electrochem. Soc., 157, B1081, 2010.
  3. J.B. Siegel, A.G. Stefanopoulou, S. Yesilyurt, “Reduced complexity models for water management and anode purge scheduling in DEA operation PEMFCs,” ECS Trans., 33(1), 1583, 2010.
  4. J.B. Siegel, A.G. Stefanopoulou, S. Yesilyurt, “Modeling and simulations of PEMFCs operating with periodically purged dead-ended anode channels,” Eights Int. Fuel Cell Science, Eng. and Tech. Conf., FuelCell2010, Brooklyn, New York, USA, June 2010.
  5. J. B. Siegel, A.G.Stefanopoulou, S. Yesilyurt, “Extracting model parameters and paradigms from neutron imaging of dead-ended anode operation,” Seventh Int. Fuel Cell Science, Eng. and Tech. Conf., FuelCell2009, Newport Beach, CA, June 2009.
  6. J.B. Siegel, A.G. Stefanopoulou, S. Yesilyurt, “Effects of nitrogen and water accumulation in the dead-ended anode operation of PEM fuel cells,” In 215th Electrochem. Soc. Meeting, 359, 2009.
  7. S. Yesilyurt, “Modeling and simulations of deformation and transport in PEM fuel cells,” Sixth Int. Fuel Cell Science, Engineering and Technology Conference (FuelCell08), Denver,Colorado, USA, ASME, June 2008.
  8. S. Yesilyurt, “Three dimensional simulations of transient response of PEM fuel cells,” ASME Int. Mechanical Eng. Congress and Exhibition, Seattle, USA, ASME, November, 2007.
  9. M.F. Serincan, S. Yesilyurt, “Transient analysis of Proton Electrolyte Membrane Fuel Cells (PEMFC) at Startup and Failure”, Fuel Cells, 7(2), 118-127, 2007.
  10. M.F. Serincan, S. Yesilyurt, “Modeling Transients of a Proton Electrolyte Membrane Fuel Cell (PEMFC),” Proceedings International Hydrogen Energy Congress and Exhibition IHEC 2005 , Istanbul, Turkey, 13-15 July 2005.
  11. M.F. Serincan, S. Yesilyurt, “Modeling Transient Water Transport in a Proton Electrolyte Membrane Fuel Cells (PEMFC) with Interdigitated Flow Fields,” Proceedings International Hydrogen Energy Congress and Exhibition IHEC 2005 , Istanbul, Turkey, 13-15 July 2005.
  12. M.F. Serincan, S. Yesilyurt,”An Analysis of a Proton Electrolyte Membrane Fuel Cell (PEMFC) at Start-ups and Failures” Lucerne Fuel Cell Forum 2005, 4-8 July 2005.

 



Design of Bio-Inspired Micro Swimming Robots for Medical Tasks


Microscopic devices that can be used in diagnostic tasks and minimally invasive surgical applications are the subject of an extremely popular research and development activities which attract attention from researchers, policy makers, investors and the public. The success of these devices relies on a multidisciplinary approach that must bring together biology, mechanics, electronics and materials research.

We aim to design and demonstrate a biologically-inspired propulsion mechanism that uses a traveling planar-wave actuator, which does not cause excessive waste, heat, and mechanical stress within the human body.  We have  two and three dimensional models of  micropumps that use traveling-plane waves as a pumping mechanism, and three-dimensional transient model of an autonomous swimmer that propels itself with the traveling-plane waves on its tail.


3D swimmer

Micropump

 

3D swimming capsule and the pressure field created near the tail (left); pressure (color shade) and flow field (velocity arrows) created by traveling-plane waves on a thin-film strip in a 3D rectangular channel (right).

Projects



Publications

  1. A.F. Tabak, S. Yesilyurt, “Validated reduced order models for simulating trajectories of bio-inspired artificial micro-swimmers,” Third Joint US-European Fluids Engineering Summer Meeting and Eighth Int. Conf. on Nanochannels, Microchannels and Minichannels (FEDSM2010-ICNMM2010), 2010.
  2. A.F. Tabak, S.Yesilyurt, “Modeling and simulations of the motion of bio-inspired micro swimming robots,” NEMB2010: Proc. of the ASME First Global Congress on Nanoengineering for Medicine and Biology-2010, 2010.
  3. M. Koz, S. Yesilyurt, “Simulation-based analysis of the micropropulsion with rotating corkscrew motion of flagella,” ASME 2009 Fluids Engineering Div. Summer Mtg., (FEDSM09) Aug. 2-6, 2009, Vail, Colorado, USA, 2009.
  4. A.F. Tabak, S. Yesilyurt, “Simulation-based analysis of flow due to traveling-plane-wave deformations on elastic thin-film actuators in micropumps”, Microfluidics and Nanofluidics,vol 4, no 6, pp 489-500, 2008.
  5. M. Koz, S. Yesilyurt, “Simulations of microflows induced by rotation of spirals in microchannels,” Proc. of SPIE, vol 6886, Microfluidics, BioMEMS, and Medical Microsystems VI, ed. Wang, Wanjun, Vauchier, Claude, Jan. 2008.
  6. M. Koz, S. Yesilyurt, “Simulation-based analysis of a biologically-inspired micropump with a rotating spiral inside a microchannel,” 6th Int. Conf. on Nanochannels, Microchannels and Minichannels, Darmstadt, Germany, ASME, June 2008.
  7. A. F. Tabak, A. Solak, E. Y. Erdem, C. Akcan, S. Yesilyurt, "Simulation-based analysis of 3D flow inside a micropump with passive valves," ASME Int. Mechanical Eng. Congress and Exhibition, Seattle, USA, ASME, November, 2007.
  8. A. F. Tabak, S. Yesilyurt, "Numerical analysis of planar wave propagation based micropropulsion system," ASME Int. Mechanical Eng. Congress and Exhibition, Seattle, USA, ASME, November, 2007.
  9. A.F. Tabak, S. Yesilyurt, "Numerical Analysis of the 3D Flow Induced by Propagationon of Plane-Wave Deformations on Thin MembraneS Inside Microchannels", Proceedings of the 5th International Conference on Nanochannels, Microchannels & Minichannels, ICNMM2007, Puebla, Mexico, June 18-20, 2007.
  10. A.F. Tabak, S. Yesilyurt, “Numerical simulations and analysis of a micropump actuated by traveling plane waves” SPIE-Photonics West, MOEMS-MEMS, San Jose, 20-25 Jan. 2007.
  11. A.F. Tabak, S. Yesilyurt, “Numerical Simulations of a Traveling Plane-Wave Actuator for Microfluidic Applications, Proceedings of the COMSOL Users Conference, Boston, October 22-24, 2006, ed. Jeri’Ann Hiller, ISBN 0-9766792-2-1.