CURRENT PROJECTS

• Drop formation in microfluidic channels
• Interfacial dynamics in complex fluids
  
• Simulation of polymer foaming
  
• Self-assembly of micro-particles and droplets
• Smart spacer in displacement flows
• Paste extrusion of PTFE
  
• Motion of solid particles in yield-stress fluids
  
  

  (with Ian Frigaard and Mark Martinez)

  The motion of particles in viscoplastic fluids is a mathematically difficult problem because the yield surface has to be determined as part of the solution. This surface is more elusive than the internal boundaries that we deal with in two-phase flows since they are not material surfaces. Most previous studies on flow of yield-stress fluids have relied on regularizing the yield criterion, in certain cases at the expense of a rigorous understanding of the nature of the yielding process (See related work). In this project, we are pursuing a variational formulation that allows us to study the yield surface from a variational inequality.