A5070516882- Electrohydrodynamics and Fluid Dynamics
- Fluid Dynamics and Heat Transfer
- Innovative Microfluidic and Catalytic Techniques Innovation
- Mass Spectrometry Techniques and Applications
- Particle Dynamics in Fluid Flows
- Microfluidic and Capillary Electrophoresis Applications
- Fluid Dynamics and Mixing
- Fluid Dynamics and Turbulent Flows
- Microfluidic and Bio-sensing Technologies
- Plant Surface Properties and Treatments
- Electrowetting and Microfluidic Technologies
- Surface Modification and Superhydrophobicity
- Silk-based biomaterials and applications
- Aerosol Filtration and Electrostatic Precipitation
- Power Transformer Diagnostics and Insulation
- Electrospun Nanofibers in Biomedical Applications
- Fluid Dynamics and Thin Films
- Rheology and Fluid Dynamics Studies
- Inhalation and Respiratory Drug Delivery
- Silkworms and Sericulture Research
- Advanced X-ray Imaging Techniques
- Viral Infectious Diseases and Gene Expression in Insects
- Enzyme Structure and Function
- Cyclone Separators and Fluid Dynamics
- Fluid Dynamics Simulations and Interactions
Universidad de Sevilla
2016-2025
European Telecommunications Standards Institute
2023
IVI Sevilla Clinic
2017
University of Southern California
1991
We report a method to generate steady coaxial jets of immiscible liquids with diameters in the range micrometer/nanometer size. This compound jet is generated by action electro-hydrodynamic (EHD) forces diameter that ranges from tens nanometers micrometers. The eventual breakup results an aerosol monodisperse droplets outer liquid surrounding or encapsulating inner one. Following this approach, we have produced capsules varying between 10 and 0.15 micrometers, depending on running parameters.
Here we report a simple microfluidics phenomenon which allows the efficient mass production of micron size gas bubbles with perfectly monodisperse and controllable diameter. It resorts on self-excited breakup (which locks at certain frequency) short microligament coflowing in focused liquid stream. In this work, describe physics obtain closed expressions for bubble diameter as function properties, geometry, flow parameters, from large set experimental results.
A new class of microscopic jet flows is here reported: for a certain range physical parameters and geometrical configurations, perfectly steady liquid thread can be formed by laminar accelerating gas stream, eventually giving rise to nearly monodisperse fine spray. Some interesting characteristics many applications this robust versatile flow related atomization technique are highlighted. Concentric multicomponent threads also produced. theoretical model presented that shows agreement with...
Abstract The new European X-ray Free-Electron Laser is the first free-electron laser capable of delivering pulses with a megahertz inter-pulse spacing, more than four orders magnitude higher previously possible. However, to date, it has been unclear whether would indeed be possible measure high-quality diffraction data at pulse repetition rates. Here, we show that structures can obtained using currently available operating conditions XFEL. We present two complete sets, one from well-known...
An analytical cone-jet solution for the electrohydrodynamic atomization of liquids has been found an asymptotic model assuming infinitely long and thin emitted jet. Universal expressions electric current, jet shape, charge distribution, surface charge, other essential quantities are obtained as functions liquid properties flow rate. The agreement with published experiments is good.
The Flow Focusing platform is especially advantageous for micro- and nanoparticle production. This versatile technique amenable to designing the size, surface treatment internal topology of particles; mechanical stresses are minimal-an optimal feature manipulation delicate substances. Multiplexing high-rate production readily implemented. Adaptive operational design can lead, in one single step, finely tuned microcapsules encasing different products within a targeted morphology. achievement...
Capillary cone jets are natural microfluidic structures arising in steady capillary tip streaming, whose paradigms electrospray and flow focusing phenomena. In this work, we make a profound revision of the basic underlying physics generic from thousands experimental measurements, most them reported literature. First, boundaries stability region jetting calculated. We describe these limitations by instability mechanisms associated with local structure issuing jet global behavior meniscus....
A systematic dimensional rationale is proposed here to analyse the electrohydro-dynamic equations governing liquid electrospraying phenomena in well-known steady cone-jet mode with no ambient discharges. As a result, general, unified description of complete parametrical space for emitted current and droplet size given. Four main distinct subspaces, their relevant boundaries corresponding scaling laws are identified. Laws already fit appropriate region, previously unknown found. closed...
Dripping, jetting and tip streaming have been studied up to a certain point separately by both fluid mechanics microfluidics communities, the former focusing on fundamental aspects while latter applications. Here, we intend review this field from global perspective considering linking two sides of problem. First, present theoretical model used study interfacial flows arising in droplet-based microfluidics, paying attention three elements commonly applications: viscoelasticity, electric...
The collapse of a bubble radius R_{o} at the surface liquid generating jet and subsequent first drop R is universally scaled using Ohnesorge number Oh=μ/(ρσR_{o})^{1/2} critical value Oh^{*} below which no droplet ejected; ρ, σ, μ are density, tension, viscosity, respectively. First, flow field analysis ejection yields scaling with velocity V as R/l_{μ}∼(V/V_{μ})^{-5/3}, where l_{μ}=μ^{2}/(ρσ) V_{μ}=σ/μ. This resolves problem curvature reversal, prelude to formation. In addition, energy...
We present a robust and computationally efficient numerical scheme for simulating steady electrohydrodynamic atomization processes (electrospray). The main simplification assumed in this is that all the free electrical charges are distributed over interface. A comparison of results with those calculated volume-of-fluid method showed presented here accurately describes flow pattern within entire liquid domain. Experiments were performed to partially validate predictions. simulations...
Electrohydrodynamically (EHD) driven capillary jets are analysed in this work the parametrical limit of negligible charge relaxation effects, i.e. when electric time liquid is small compared to hydrodynamic times. This regime can be found electrospraying liquids Taylor's charged formed a steady regime. A quasi-one-dimensional EHD model comprising temporal balance equations mass, momentum, charge, across surface, and inner outer fields presented. The forms take into account surface convection...
This letter describes the generation of small turbulence scales in connection with a singular back-flow pattern leading to efficient atomization. A simple pneumatic atomizer configuration results, tenfold efficiency increase over available plain-jet air-blast atomizers. Back-flow atomization derives from global bifurcation liquid-gas flow pattern; is triggered by single geometrical parameter atomizer. The extremely geometry involved can be implemented down micrometric scale, thus opening...
In a recent work [Phys. Rev. Lett. 87, 274501 (2001)], method to produce monodisperse microbubbles was described. The physics of the phenomenon explained in terms absolute instabilities gas microjet formed when liquid stream which surrounds coflowing is forced through small orifice. Now, much more consistent physical picture describe corrects prior assumptions presented. Consequently, simpler and universal scaling law for microbubble size finally obtained involves orifice diameter gas/liquid...
We aim to establish the scaling laws for both minimum rate of flow attainable in steady cone–jet mode electrospray, and size resulting droplets that limit. Use is made a small body literature on Taylor cone–jets reporting precise measurements transported electric current droplet as function liquid properties rate. The projection data onto an appropriate non-dimensional parameter space maps region bounded by state. To explain these experimental results, we propose theoretical model based...
The liquid cone-jet mode can be produced upon stimulation by a coflowing gas sheath. Most applications deal with the jet breakup, leading to either of two droplet generation regimes: Jetting and dripping. flow pattern is explored direct axisymmetric volume fluid (VOF) numerical simulation; its evolution studied as rate increased around jetting-dripping transition. As observed in other focused flows such electrospraying cones steady thread emission, displays strong recirculating within...