In a previous work, two-dimensional film flows were modelled using weighted-residual approach that led to four-equation model consistent at order , accounts for inertia effects due the deviations of velocity profile from parabolic shape, and closely follows asymptotic long-wave expansion in appropriate limit. Comparisons wave properties with experiments direct numerical simulations show good agreement range parameters which wavy motion is reported experiments.The stability travelling waves...

Abstract Surface galectin has been shown to contribute dysfunctions of human tumour-infiltrating lymphocytes (TILs). We show here that galectin-covered CD8 TILs produce normal amounts intracellular cytokines, but fail secrete them because defective actin rearrangements at the synapse. The non-secreting also display reduced adhesion their targets, together with LFA-1 recruitment and activation These defects are relieved by releasing surface galectin. As mild blockade on blood T cells emulate...

Abstract Most commercial microfluidic droplet generators rely on the planar flow-focusing configuration implemented in polymer or glass chips. The geometry, however, suffers from many limitations and drawbacks, such as need of specific coatings use dedicated surfactants, depending fluids play. On contrary, thanks to their axisymmetric capillary-based are a priori not fluid-dependent. Nevertheless, they have never reached market because assembly requires fastidious scalable fabrication...

Abstract Concentration gradients are at the basis of many natural phenomena and hold great importance in human plant biology. This basic phenomenon has inspired material scientists to confer novel original properties materials with numerous biomedical pharmaceutical applications such as drug discovery, controlled release drugs, tissue engineering, orthopedic implants time–temperature indicators, amongst others. While generation solution is well described, their incorporation solid remains...

We consider the dynamics of a thin liquid film falling down uniformly heated wall. The heating sets up surface tension gradients that induce thermocapillary stresses on free surface, thus affecting evolution film. model this flow by using gradient expansion combined with Galerkin projection polynomial test functions for both velocity and temperature fields. obtain equations amplitudes at first- second-order in parameter. These are fully compatible close to criticality Benney long-wave...

The Benney equation including thermocapillary effects is considered to study a liquid film flowing down homogeneously heated inclined wall. link between the finite-time blow-up of and absence one-hump travelling-wave solution associated dynamical system accurately demonstrated in whole range linearly unstable wavenumbers. Then boundary tracked space parameters accounting for flow rate, surface tension, inclination thermocapillarity. In particular, latter two can strongly reduce validity...

The present theoretical study focuses on the dynamics of a thin liquid film falling down vertical plate with nonuniform, sinusoidal temperature distribution. results are compared to those obtained in case uniform governing evolution equation for thickness profile based long-wave theory accounts two instability mechanisms related thermocapillarity. first mechanism is due an inhomogeneity at liquid–gas interface induced by perturbations thickness, when heat transfer gas phase present, while...

We analyse the regularized reduced model derived in Part 1 (Ruyer-Quil et al . 2005). Our investigation is two-fold: (i) we demonstrate that linear stability properties of are good agreement with Orr–Sommerfeld analysis linearized Navier–Stokes/energy equations; (ii) show existence nonlinear solutions, namely single-hump solitary pulses, for widest possible range parameters. also scrutinize influence Reynolds, Prandtl and Marangoni numbers on shape, speed, flow patterns temperature...

We present new insights and results for the problem of a film falling down heated wall: (i) treatment mixed heat flux boundary condition on substrate; (ii) development long-wave theory large Péclet numbers; (iii) refined energy equation based high-order Galerkin projection in terms polynomial test functions which satisfy all conditions; (iv) time-dependent computations free-surface height interfacial temperature; (v) numerical solution full equation; (vi) demonstration existence thermal...

When transported by a pressure driven flow in cylindrical pipe, bubbles may exhibit very fast velocities. In this paper, we show that, when the are largely deformable, that is, at large capillary numbers Ca, velocity of bubble can be larger than maximal transports them. We call regime "super-fast". However, situation changes inertia comes play for increasing Reynolds Re, and relative drops sufficiently Laplace number, defined as La = Re/Ca. article, uncover conditions which super-fast exists...

We analyse the stability of a thin film falling under influence gravity down locally heated plate. Marangoni flow, due to local temperature changes influencing surface tension, opposes gravitationally driven Poiseuille flow and forms horizontal band at upper edge heater. The thickness increases with tension gradient, until an instability rivulet structure periodic in transverse direction. study dependence critical number, non-dimensional measure gradient onset instability, on associated Bond...

The role of surface rheology in fundamental fluid dynamical systems, such as liquid coating flows and soap film formation, is poorly understood. We investigate the viscosity classical film-coating problem. propose a theoretical model that predicts thickening based on purely surface-viscous theory. theory supported by set new experimental data demonstrates slight even at very high surfactant concentrations for which Marangoni effects are irrelevant. experiments represent regime has not been...

An antibubble is a spherical air film that immersed in surfactant mixture and drains under the action of hydrostatic pressure. A dynamical model this proposed accounts for surface shear viscosity effects case purely viscous interfaces, which applies surfactants whose adsorption rate much larger than advection at concentration above critical micelle concentration. Our shows lifetime antibubbles increases with viscosity, denoted ε, value measured independently, all agreement experimental...

Tesla valve is a particular check that can be used as fluidic diode, but has no moving parts, and shows promising applications in macro- microfluidic systems. Fluidic diode indicates the inflow direction of affects pressure drop, allowing fluid to pass easily one while presenting higher resistance reverse direction. Although previous studies have shown performance such valves significantly improved by placing series units compact cascade, reason still unclear. In this study, effect internal...

Flow features for 2D falling films flowing under an inclined plane are presented based on the weighted integral boundary value model and compared with direct numerical simulations. For a transition to circulating waves, universal critical ratio of maximum-to-substrate film thickness is found.

The behavior of thin liquid films is known to be strongly affected by the presence surfactants at interfaces. detailed mechanism which latter enhance film stability still a matter debate, in particular concerning influence surface elastic effects on hydrodynamic boundary condition liquid/air In present work, "twin" models neglecting surfactant transport interfaces are proposed describe coating onto solid plate (Landau-Levich-Derjaguin configuration) as well soap pulling (Frankel...

Liquid films flowing down the underside of inclined plates are subject to interaction between hydrodynamic and Rayleigh-Taylor (R-T) instabilities causing a patterned wavy topology at free surface. The R-T instability results from denser liquid film being located above less dense ambient gas, deforming into an array droplets, which eventually drip if no saturation mechanism arises. Such can actually be provided by fluid motion along plate. Using weighted integral boundary layer model, this...