Book contents
- Frontmatter
- Contents
- Preface
- 1 Introduction
- 2 Selected Basic Flows and Forces
- Part I Collision of Liquid Jets and Drops with a Dry Solid Wall
- 3 Jet Impact onto a Solid Wall
- 4 Drop Impact onto a Dry Solid Wall
- 5 Drop Impact onto Dry Surfaces with Complex Morphology
- Part II Drop Impacts onto Liquid Surfaces
- Part III Spray Formation and Impact onto Surfaces
- Part IV Collisions of Solid Bodies with Liquid
- Part V Solid–Solid Collisions
- Index
- References
5 - Drop Impact onto Dry Surfaces with Complex Morphology
from Part I - Collision of Liquid Jets and Drops with a Dry Solid Wall
Published online by Cambridge University Press: 13 July 2017
Book contents
- Frontmatter
- Contents
- Preface
- 1 Introduction
- 2 Selected Basic Flows and Forces
- Part I Collision of Liquid Jets and Drops with a Dry Solid Wall
- 3 Jet Impact onto a Solid Wall
- 4 Drop Impact onto a Dry Solid Wall
- 5 Drop Impact onto Dry Surfaces with Complex Morphology
- Part II Drop Impacts onto Liquid Surfaces
- Part III Spray Formation and Impact onto Surfaces
- Part IV Collisions of Solid Bodies with Liquid
- Part V Solid–Solid Collisions
- Index
- References
Summary
Surface texture, e.g. roughness, porosity, wettability and chemical composition can significantly affect the outcome of drop impact. Section 5.1 deals with the splashing threshold on rough, textured and also porous solid surfaces. In Section 5.2 an impact of a single Newtonian drop near a hole in a flat substrate is considered as a simplified model of drop spreading on a porous substrate. The experiments described in Section 5.3 deal with drop impacts of such different liquids as water and oily Fluorinerts onto suspended thin membranes with microscopic pores of different wettability. They reveal that liquid penetration is possible even through a non-wettable porous medium if the impact velocity is high enough. A similar conclusion stems from the experiments with water drop impacts onto membranes coated with much less permeable nanofiber layers discussed in Section 5.4. In the case of nanofiber mats deposited onto impermeable surfaces, drop splashing and bouncing after impact can be fully suppressed, as the experiments of Section 5.5 show. The reason for the phenomena observed in Sections 5.3–5.5 is the hydrodynamic focusing of liquid brought by a millimeter-sized drop into micron-sized pores. The theory of the hydrodynamic focusing phenomenon is given in Section 5.6, and the results are illustrated experimentally by the amazing fact that liquid velocity in the jets which penetrated through the entire porous medium thickness is higher than that in the impacting drop, even though the viscous dissipation in flow through porous medium is extremely high. Liquid penetration following drop impact onto a nonwettable porous medium is also visualized in the experiments with the entrained seeding particles in Section 5.7, which also contains the evaluation of the critical filter thickness which can be fully penetrated in spite of the viscous dissipation in the pores. Drop impacts onto hot surfaces covered with nanofiber mats also reveal significant enhancement of surface cooling due to the hydrodynamic focusing. The latter sustains the contact of liquid coolant with the hot surface underneath and thus facilitates complete liquid vaporization and significant heat removal in the form of latent heat of evaporation (Section 5.8).
- Type
- Chapter
- Information
- Collision Phenomena in Liquids and Solids , pp. 155 - 252Publisher: Cambridge University PressPrint publication year: 2017
References
, and (1989). Theory of Fluid Flows through Natural Rocks, Kluwer Academic Publishers, Dordrecht.
(2002). An Introduction to Fluid Dynamics, Cambridge University Press.
, and (2008). Pressure-driven fluidic delivery through carbon tube bundles, Lab Chip
8: 152–160.Google Scholar
(1993). Air Filtration: An Integrated Approach to the Theory and Applications of Fibrous Filters, Pergamon Press, Oxford.
, , , and (2009). To grate a liquid into tiny droplets by its impact on a hydrophobic microgrid, Appl. Phys. Lett.
95: 254102.Google Scholar
(2006). Groundwater Hydraulics and Pollutant Transport, Waveland Press, Long Grove.
, , , , , and (2004). Clogging of fibre filters by submicron droplets. Phenomena and influence of operating conditions, J. Aerosol Sci.
35: 263–278.Google Scholar
, and (2004). Capillarity and Wetting Phenomena: Drops, Bubbles, Pearls, Waves, Springer, New York.
, , and (2012). Candle soot as a template for a transparent robust superamphiphobic coating, Science
335: 67–70.Google Scholar
, and (1975). Effect of contact deformations on the adhesion of particles, J. Colloid Interface Sci.
53: 314–326.Google Scholar
, , , , , , and (2006). Ionic liquid droplet as e-microreactor, Anal. Chem.
78: 4909–4917.Google Scholar
, , and (2010). Drop dynamics after impact on a solid wall: theory and simulations, Phys. Fluids
22: 062101.Google Scholar
, , and (2007). Asymmetric electrowetting moving droplets by a square wave, Lab Chip
7: 1330–1335.Google Scholar
, and (2007). Electrospinning of micro-and nanofibers: fundamentals in separation and filtration processes, J. Eng. Fibers Fabrics
3: 488.Google Scholar
, , and (2005). Clogging of fibrous filters by liquid aerosol particles: Experimental and phenomenological modelling study, Chem. Eng. Sci.
60: 2751–2762.Google Scholar
and (2006). The “Lotus effect” explained: two reasons why two length scales of topography are important, Langmuir
22: 2966–2967.Google Scholar
and (2008). Teflon is hydrophilic. Comments on definitions of hydrophobic, shear versus tensile hydrophobicity, and wettability characterization, Langmuir
24: 9183–9188.Google Scholar
, , , , , and (2007). Mimicking a Stenocara beetle's back for microcondensation using plasmachemical patterned superhydrophobic-superhydrophilic surfaces, Langmuir
23: 689–693.Google Scholar
and (2007). Table of Integrals, Series and Products, 7th edn, Elsevier, Amsterdam.
and (2009). Superhydrophobic and oleophobic fibers by coaxial electrospinning, Langmuir
25: 9454–9462.Google Scholar
, , , and (2009). Electrowetting control of Cassie-to-Wenzel transitions in superhydrophobic carbon nanotube-based nanocomposites, ACS Nano
3: 3031–3036.Google Scholar
and (2003). Video-speed electronic paper based on electrowetting, Nature
425: 383–385.Google Scholar
, and (2003). Multiple equilibrium droplet shapes and design criterion for rough hydrophobic surfaces, Langmuir
19: 4999–5003.Google Scholar
(1974). Applied and Computational Complex Analysis, Vol. 3, John Wiley & Sons, New York.
, and (2004). A lotus-leaf-like superhydrophobic surface: A porous microsphere/nanofiber composite film prepared by electrohydrodynamics, Angew. Chem. Int. Ed.
116: 4338–4341.Google Scholar
and (2007). Evaluation of jet impingement, spray and microchannel chip cooling options for high heat flux removal, Heat Transf. Eng.
28: 911–923.Google Scholar
, and (2006). Liquid–paper interactions during liquid drop impact and recoil on paper surfaces, Colloid Surf. A-Physicochem. Eng.
280: 203–215.Google Scholar
, and (2005). Microflows and Nanoflows: Fundamentals and Simulation, Springer, New York, Heidelberg.
(2005). Impact of drops on a water-covered sand bed: erosion, entrainement and pattern formation, Europhys. Lett.
71: 400–406.Google Scholar
, , and (2007). Strong charge trapping and bistable electrowetting on nanocomposite fluoropolymer: BaTiO3 dielectrics, Appl. Phys. Lett.
90: 212906.Google Scholar
(2007). Spray cooling heat transfer: The state of the art, Int. J. Heat Fluid Flow
28: 753–767.Google Scholar
, , and (2004). From rolling ball to complete wetting: the dynamic tuning of liquids on nanostructured surfaces, Langmuir
20: 3824–3827.Google Scholar
and (2004). Variable-focus liquid lens for miniature cameras, Appl. Phys. Lett.
85: 1128–1130.Google Scholar
and (1973). Methods of Theory of Functions of Complex Variable, Nauka, Moscow. (in Russian).
and (2011). Dynamic wetting and spreading characteristics of a liquid droplet impinging on hydrophobic textured surfaces, Langmuir
27: 6565–6573.Google Scholar
, , and (2013). Dynamic electrowetting-ondielectric (DEWOD) on unstretched and stretched Teflon, Langmuir
29: 7758–7767.Google Scholar
, , , , , and (2010). Drop impact, spreading, splashing, and penetration into electrospun nanofiber mats, Langmuir
26: 9516–9523.Google Scholar
(1962). Physiochemical Hydrodynamcis, Prentice-Hall, Englewood Cliffs.
, , and (2011). Water droplet motion control on superhydrophobic surfaces: exploiting the Wenzel-to-Cassie transition, Langmuir
27: 2595–2600.Google Scholar
(1966). Mechanics of Gases and Liquids, Pergamon Press, Oxford.
(1966). Heat and Mass Transfer in Capillary-Porous Bodies, Pergamon Press, Oxford.
, , and (2010). Directed rebounding of droplets by microscale surface roughness gradients, Appl. Phys. Lett.
96: 234103.Google Scholar
and (2009). Molecular-to-large-scale heat transfer with multiphase interfaces: Current status and new directions, J. Heat Transf.-Trans. ASME
131: 121001.Google Scholar
(1988). Drop penetration into a thin porous medium, J. Colloid Interface Sci.
123: 161–169.Google Scholar
(2007). The equilibrium contact angle, in
, and (eds.), Springer Handbook of Experimental Fluid Mechanics, Springer, Berlin, chapter 3.3.1, pp. 106– 112.
and (2006). Complex Analysis, Jones and Bartlett Publishers, Boston.
and (2005). Electrowetting: from basics to applications, J. Phys. Condens. Matter
17: 705–774.Google Scholar
, and (1995). Droplet-wall collisions: experimental studies of the deformation and breakup process, Int. J. Multiph. Flow
21: 151–173.Google Scholar
, , and (2010). Quantitative testing of robustness on superomniphobic surfaces by drop impact, Langmuir
26: 18369–18373.Google Scholar
, , , , and (2010). The role of solid surface structure on dropwise phase change processes, Int. J. Heat Mass Transf.
53: 910–922.Google Scholar
and (2009). Heat transfer correlation for intermittent spray impingement: a dynamic approach, Int. J. Therm. Sci.
48: 1853–1862.Google Scholar
, , , , , , , , , , , , and (2012). Highly stretchable electric circuits from a composite material of silver nanoparticles and elastomeric fibres, Nat. Nanotechnol.
7: 803–809.Google Scholar
and (1974). Complex Variables, John Wiley & Sons, New York.
and (1998). Influence of surface roughness on liquid drop impact, J. Colloid Interface Sci.
203: 16–30.Google Scholar
, and (2008). Parametric study of liquid droplets impinging on porous surfaces, Appl. Math. Model.
32: 341–361.Google Scholar
, , and (2007). Electrospinning of nanofibers from polymer solutions and melts, Adv. Appl. Mech.
41: 43–346.Google Scholar
, , and (2004). Transient and steady shapes of droplets attached to a surface in a strong electric field, J. Fluid Mech.
516: 349–377.Google Scholar
, and (1998). Handbook of Heat Transfer,McGraw-Hill, New York.
(2009). Inertia dominated drop collisions. II. An analytical solution of the Navier– Stokes equations for a spreading viscous film, Phys. Fluids
21: 052104.Google Scholar
, and (2009). Inertia dominated drop collisions. I. On the universal flow in the lamella, Phys. Fluids
21: 052103.Google Scholar
, and (2015). Drop splashing induced by target roughness and porosity: the size plays no role, Adv. Colloid Interface Sci.
222: 615–621.Google Scholar
, and (2002). Normal impact of a liquid drop on a dry surface: model for spreading and receding, Proc. R. Soc. London Ser. A-Math.
458: 1411–1430.Google Scholar
, and (1989). Colloidal Dispersions, Cambridge University Press.
, , and (2015). Impact of aqueous suspension drops onto non-wettable porous membranes: Hydrodynamic focusing and penetration of nanoparticles, Colloid Surf. A-Physicochem. Eng.
467: 31–45.Google Scholar
, , and (2012). Drop impacts on electrospun nanofiber membranes, Soft Matter
8: 3957–3970.Google Scholar
, , and (2003). Equilibrium behavior of sessile drops under surface tension, applied external fields, and material variations, J. Appl. Phys.
93: 5794–5811.Google Scholar
, , , and (2007). Deformation of alumina droplets on micro-patterned substrates under plasma spraying conditions, J. Therm. Spray Technol.
16: 300–305.Google Scholar
and (2014). Drop impact cooling enhancement on nano-textured surfaces. Part I: Theory and results of the ground (1g) experiments, Int. J. Heat Mass Transf.
70: 1095–1106.Google Scholar
, and (2011). Thorny devil nanotextured fibers: the way to cooling rates on the order of 1 kW/cm2, Langmuir
27: 215–226.Google Scholar
, , and (2005). Spreading behavior of an impacting drop on a structured rough surface, Phys. Fluids
17: 100608.Google Scholar
and (2007). Spray cooling on micro structured surfaces, Int. J. Heat Mass Transf.
50: 4089–4097.Google Scholar
, , , , and (2009). Nanofiber coating of surfaces for intensification of drop or spray impact cooling, Int. J. Heat Mass Transf.
52: 5814–5826.Google Scholar
, , , and (2003). Spreading of liquid drops over porous substrates, Adv. Colloid Interface Sci.
104: 123–158.Google Scholar
(2002). The ejecta sheet generated by the impact of a drop, J. Fluid Mech.
451: 373–381.Google Scholar
, and (2008). High-speed imaging of drops and bubbles, Annu. Rev. Fluid Mech.
40: 257–285.Google Scholar
(1989). Granular Filtration of Aerosols and Hydrosols, Butterworths, Boston.
, , , and (2009). Drop impact upon micro- and nanostructured superhydrophobic surfaces, Langmuir
25: 12293–12298.Google Scholar
, , and (2010). How micropatterns and air pressure affect splashing on surfaces, Langmuir
26: 16090–16095.Google Scholar
, and (1999). Limiting phenomena for the spreading of water on polymer films by electrowetting, Eur. Phys. J. B
11: 583–591.Google Scholar
and (2009). Application of two-phase spray cooling for thermal management of electronic devices, IEEE Trans. Components Packag. Technol.
32: 784–793.Google Scholar
and (2005). Saturation effects in dynamic electrowetting, Appl. Phys. Lett.
86: 054104.Google Scholar
, , , , and (2007). Polarity-dependent electrochemically controlled transport of water through carbon nanotube membranes, Nano Lett.
7: 697–702.Google Scholar
, , , , , and (2011a). Nonisothermal drop impact and evaporation on polymer nanofiber mats, Phys. Rev. E
83: 036305.Google Scholar
, , , , , and (2011b). Inverse-Leidenfrost phenomenon on nanofiber mats on hot surfaces, Phys. Rev. E
84: 036310.Google Scholar
and (1999). Single drop impact onto liquid films: neck distortion, jetting, tiny bubble entrainment, and crown formation, J. Fluid Mech.
385: 229–254.Google Scholar
(1936). Resistance of solid surfaces to wetting by water, Ind. Eng. Chem.
28: 988–994.Google Scholar
, , , , , and (2011). Bioinspired self-repairing slippery surfaces with pressure-stable omniphobicity, Nature
477: 443–447.Google Scholar
(2007). Liquid drop splashing on smooth, rough, and textured surfaces, Phys. Rev. E
75: 056316.Google Scholar
, , , , , and (2010). Experimental study of impingement spray cooling for high power devices, Appl. Therm. Eng.
30: 1225–1230.Google Scholar
, , and (2003). Tunable and latchable liquid microlens with photopolymerizable components, Adv. Mater.
15: 940–943.Google Scholar
(2006). Drop impact dynamics: splashing, spreading, receding, bouncing …
, Annu. Rev. Fluid Mech.
38: 159–192.Google Scholar
, and (2014). Fundamentals and Applications of Micro- and Nanofibers, Cambridge University Press.
, and (2009). Fluid Flow, Heat Transfer and Boiling in Micro- Channels, Springer, Heidelberg.
and (2007). Micro air bubble manipulation by electrowetting on dielectric (EWOD): transporting, splitting, merging and eliminating of bubbles, Lab Chip
7: 273–280.Google Scholar
, and (2005). Effects of hydraulic pressure on the stability and transition of wetting modes of superhydrophobic surfaces, Langmuir
21: 12207–12212.Google Scholar
, , , , and (2006). Electrowetting of aligned carbon nanotube films, J. Phys. Chem. B
110: 15945–15950.Google Scholar
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