Geometric scaling of purely-elastic flow instabilities
  We present a combined experimental, numerical and theoretical investigation of the geometric scaling of the onset of a purely-elastic flow instability in a serpentine channel. Good qualitative agreement is obtained between experiments, using dilute solutions of flexible polymers in microfluidic devices, and two-dimensional numerical simulations using the UCM model. The results are confirmed by a simple theoretical analysis, based on the dimensionless criterion proposed by Pakdel-McKinley for onset of a purely-elastic instability. 
J. Zilz, R. J. Poole, M. A. Alves, D. Bartolo, B. Levache and A.   Lindner
cond-mat.soft physics.flu-dyn