Abstract The region of acceptable quality in the space operating parameters a coating process is called window. Their limits are set by defects. For slot‐coating low‐flow limit important. It corresponds to maximum web speed at given film thickness, or minimum thickness speed, which bead remains stable. available viscocapillary model based on Landau‐Levich equation, limited small Capillary and Reynolds numbers. Under these conditions, that can be coated decreases with decreasing but many...

Conventional viscous fingering flow in radial Hele-Shaw cells employs a constant injection rate, resulting the emergence of branched interfacial shapes. The search for mechanisms to prevent development these bifurcated morphologies is relevant number areas science and technology. A challenging problem how best choose pumping rate order restrain growth amplitudes. We use an analytical variational scheme look precise functional form such optimal rate. find it increases linearly with time...

The dynamics of liquid bridges are relevant to a wide variety applications including high-speed printing, extensional rheometry, and floating-zone crystallization. Although many studies assume that the contact lines bridge pinned, this is not case for printing processes such as gravure, lithography, microcontacting. To address issue, we use Galerkin/finite element method study stretching finite volume Newtonian confined between two flat plates, one which stationary other moving. steady...

SUMMARY We discuss the use of polygonal finite elements for analysis incompressible flow problems. It is well‐known that stability mixed element discretizations governed by so‐called inf‐sup condition, which, in this case, depends on choice discrete velocity and pressure spaces. present a low‐order these spaces defined over convex partitions domain satisfies condition and, as such, does not admit spurious modes or exhibit locking. Within each element, field constant while represented usual...

Over the last years several studies have been conducted to understand emulsion formation and its behavior. In some applications, aim is phase separation of emulsions through coalescence drops, as in oil industry. this study, relationship between rheological properties oil-water interfaces drainage time a thin film two aqueous drops was investigated. Interfacial tension dilatational rheology were measured using axisymmetric drop shape analysis. We evaluated different concentrations nonionic...

Transport of emulsions in porous media is relevant to several subsurface applications. Many enhanced oil recovery (EOR) processes lead emulsion formation and as a result conformance originating the flow dispersed phase may arise. In some EOR processes, injected directly mobility control agent. Modeling extremely challenging due complex nature associated flows numerous interfaces. The descriptions based on effective viscosity are not valid when drop size same order magnitude pore-throat...

Liquid bridges with moving contact lines are found in a variety of settings such as capillary feeders and high-speed printing. Although it is often assumed that the length scale for these flows small enough inertial effects can be neglected, this not case certain applications. To address issue, we solve Navier-Stokes equations finite element method stretching liquid drop between two surfaces non-zero Reynolds numbers. We consider an axisymmetric bridge flat plate either stationary or cavity....

The optimization of architecture and weights feed forward neural networks is a complex task great importance in problems supervised learning. In this work we analyze the use particle swarm algorithm for network architectures aiming better generalization performances through creation compromise between low architectural complexity training errors. For evaluating these algorithms apply them to benchmark classification medical field. results showed that PSO-PSO based approach represents valid...

Abstract Dynamic wetting is crucial to processes where liquid displaces another fluid along a solid surface, such as the deposition of coating onto moving substrate. Numerous studies report failure dynamic past some critical process speed. However, hydrodynamic factors that influence transition remain poorly understood from an empirical and theoretical perspective. The objective this investigation determine effect meniscus confinement on onset failure. A novel experimental system designed...

This work investigates the onset of wetting failure for displacement Newtonian fluids in parallel channels. A hydrodynamic model is developed planar geometries where an advancing fluid displaces a receding along moving substrate. The evaluated with three distinct approaches: (i) low-speed asymptotic theory Cox [J. Fluid Mech. 168, 169–194 (1986)], (ii) one-dimensional (1D) lubrication approach, and (iii) two-dimensional (2D) flow solved Galerkin finite element method (FEM). Approaches...

Abstract Liquid bridges with moving contact lines are relevant in a variety of natural and industrial settings, ranging from printing processes to the feeding birds. While it is often assumed that liquid bridge two-dimensional nature, there many applications where either stretching motion or presence feature on bounding surface lead three-dimensional effects. To investigate this we solve Stokes equations using finite-element method for between two flat surfaces, one stationary moving. We...

We design and fabricate elastically tunable monodisperse microcapsules using microfluidics cross-linkable polydimethylsiloxane (PDMS). The overall stiffness of the is governed by both thickness cross-link ratio polymer shell. Flowing suspensions through constricted spaces leads to transient blockage fluid flow, thus altering flow behavior. ability tune microcapsule mechanical properties enables elastic that can be tailored for desired behavior in a broad range applications such as oil...

Abstract Characteristic substrate speeds and meniscus shapes associated with the onset of air entrainment are studied during dynamic wetting failure along a planar substrate. Using high-speed video, behaviour contact line (DCL) is recorded as tape drawn through bath glycerol/water solution. Air identified by triangular films that elongate from DCL above some critical speed. Meniscus confinement within narrow gap between stationary plate shown to delay higher for wide range liquid...

Summary This work presents a new coupled transient wellbore/reservoir thermal analytical model, consisting of combined reservoir/casing/tubing system. The model considers flow slightly compressible, single–phase fluid in homogeneous infinite–acting reservoir system and provides temperature–transient data for drawdown buildup tests at any gauge location along the wellbore. accounts Joule–Thomson (J–T), adiabatic–fluid–expansion, conduction, convection effects. wellbore–fluid mass density is...