Surface waves at the interface between two viscous fluids
  The Surface Green Function Matching analysis (SGFM) is used to study the normal modes of the interface oscillations between two non-mixed fluids by considering the difference in their densities and viscosities. The limiting case of viscous-inviscid system is used for comparison. The role of the viscosity and the density ratios on the momentum exchange and on the polarization of the surface modes is analyzed. 
Arezky H. Rodriguez, J. Marin-Antuna, H. Rodriguez-Coppola and C.   Dopazo