Biofluidics Lab

Pearling instability in a viscous jet

 

Propagating fronts in which an unstable state invades a stable state or vice versa are common features in nonlinear dissipative systems such as Rayleigh-Benard convection, Taylor-Couette flow and dentritic growth. Recent interests on front propagations in Rayleigh instability are inspired by the discovery of front propagation in lipid bilayer membrane tube, in which the application of laser tweezer to the membrane induces a periodic modulation in the radius of the tube. We studied experimentally the propagating fronts in Rayleigh instability, where a cylindrical interface between two immiscible fluids becomes unstable and undergoes fission. The cylindrical interface is produced using a viscous jet. Pearling instabilities are observed and the unstable front is found to propagate at a uniform velocity along the cylinder. The front propagation velocity is measured and compared with the recent theoretical calculation.