The interaction between a fluid and a solid surface in relative motion represents a dynamical process that is central to the problem of laminar-to-turbulent transition (and consequent drag increase) for air, sea and land vehicles, as well as long-range pipelines. This problem may in principle be alleviated via a control stimulus designed to impede the generation and growth of instabilities inhe...

We theoretically and numerically investigate the instabilities driven by diffusiophoretic flow, caused a solutal concentration gradient along reacting surface. The important control parameter is Peclet number Pe, which quantifies ratio of advection rate to diffusion rate. First, we study flow on catalytic plane in two dimensions. From linear stability analysis, obtain that for Pe larger than 8p...

Spatial structures break their symmetry under the influence of shear stress arising from fluid flow. Here, we present surface instabilities appearing on chitosan tubes when an acidic solution with various molecular weight is injected into a pool sodium hydroxide solution. At slow flow rates wrinkle-to-fold transition takes place along direction yielding banded structure. For greater injection o...

Viscoelastic fluids can exhibit striking flow instabilities under conditions where ordinary Newtonian are stable, owing to the nonlinear coupling of elastic and viscous stresses. This article provides perspectives on viscoelastic by integrating input from speakers at a recent international workshop: historical remarks, characterization flows, discussion experimental simulation tools, modern que...