scholarly journals Microdroplet nucleation by dissolution of a multicomponent drop in a host liquid

2019 ◽  
Vol 870 ◽  
pp. 217-246 ◽  
Author(s):  
Huanshu Tan ◽  
Christian Diddens ◽  
Ali Akash Mohammed ◽  
Junyi Li ◽  
Michel Versluis ◽  
...  
Keyword(s):  
Growth Dynamics ◽  
Marangoni Effect ◽  
Multicomponent Diffusion ◽  
Experimental Investigations ◽  
Spontaneous Emulsification ◽  
Liquid Drops ◽  
One Dimensional ◽  
Spontaneous Nucleation ◽  
Quantitative Understanding ◽  
Liquid Microextraction

Multicomponent liquid drops in a host liquid are very relevant in various technological applications. Their dissolution or growth dynamics is complex. Differences in solubility between the drop components combined with the solutal Marangoni effect and natural convection contribute to this complexity, which can be even further increased in combination with the ouzo effect, i.e. the spontaneous nucleation of microdroplets due to composition-dependent miscibilities in a ternary system. The quantitative understanding of this combined process is important for applications in industry, particularly for modern liquid–liquid microextraction processes. In this work, as a model system, we experimentally and theoretically explore water–ethanol drops dissolving in anethole oil. During the dissolution, we observed two types of microdroplet nucleation, namely water microdroplet nucleation in the surrounding oil at drop mid-height, and oil microdroplet nucleation in the aqueous drop, again at mid-height. The nucleated oil microdroplets are driven by Marangoni flows inside the aqueous drop and evolve into microdroplet rings. A one-dimensional multiphase and multicomponent diffusion model in combination with thermodynamic equilibrium theory is proposed to predict the behaviour of spontaneous emulsification, i.e. microdroplet nucleation, that is triggered by diffusion. A scale analysis together with experimental investigations of the fluid dynamics of the system reveals that both the solutal Marangoni flow inside the drop and the buoyancy-driven flow in the host liquid influence the diffusion-triggered emulsification process. Our work provides a physical understanding of the microdroplet nucleation by dissolution of a multicomponent drop in a host liquid.

An Analysis of Coupled Multicomponent Diffusion in Interstitial Tissue

1994 ◽  
Vol 116 (2) ◽  
pp. 164-171 ◽  
Author(s):  
P. D. Schreuders ◽  
K. R. Diller ◽  
J. J. Beaman ◽  
H. M. Paynter
Keyword(s):  
Multicomponent Diffusion ◽  
Frequency Parameter ◽  
Interstitial Tissue ◽  
Specific System ◽  
Species Concentration ◽  
One Dimensional ◽  
Jump Distance ◽  
Local Species ◽  
The Individual ◽  
Graph Form

A one-dimensional multicomponent kinetic model was developed to simulate the interstitial diffusion of macromolecules in a three component system, consisting of water, the macromolecule and the interstitial matrix. Movement of the individual components was modeled as occurring in finite jumps between discrete low energy wells along paths defined in terms of species occupation. The flow rate was expressed as a function of the local species concentration, the jump distance, and a kinetic frequency parameter. The model, implemented in pseudo-bond graph form, was examined by fitting it to data obtained for the transport of fluorescein tagged dextran to determine the kinetic constants for that specific system.

scholarly journals A model-based and experimental approach for the determination of suitable variable valve timings for cold start in partial load operation of a passenger car single-cylinder diesel engine

2018 ◽  
Vol 20 (1) ◽  
pp. 141-154 ◽  
Author(s):  
P Maniatis ◽  
U Wagner ◽  
T Koch
Keyword(s):  
Diesel Engine ◽  
Experimental Investigations ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Warm Up ◽  
One Dimensional ◽  
Engine Efficiency ◽  
Residual Gas ◽  
Dimensional Simulation ◽  
Exhaust Gas Temperature

A manipulation of the charge exchange allows controlling the amount of residual gas during engine warm-up. The residual gas during the warm-up phase leads to an increase of the exhaust gas temperature and supports to reach the exhaust after-treatment system operating temperature faster. In addition, the warm residual gas increases the combustion chamber temperature, which reduces the HC and CO emissions. However, fuel consumption increases. For that reason, such heating measures should be the best compromise of both, exhaust gas temperature increase and engine efficiency, in order to provide efficient heating strategies for passenger car diesel engines. Therefore, simulative and experimental investigations are carried out at the Institute of Internal Combustion Engines of the Karlsruhe Institute of Technology to establish a reliable cam design methodology. For the experimental investigations, a modern research single-cylinder diesel engine was set up on a test bench. In addition, a one-dimensional simulation model of the experimental setup was created in order to simulate characteristics of valve lift curves and to investigate their effects on the exhaust gas temperature and the exhaust gas enthalpy flow. These simulations were based on design of experiments (DoE), so that all characteristics can be used sustainably for modeling and explaining their influences on the engine operation. This methodology allows numerically investigating promising configurations and deriving cam contours which are manufactured for testing. To assess the potential of these individual configurations, the results obtained were compared with each other as well as with the series configuration. Results show that the combination of DoE and one-dimensional simulation for the design of camshaft contours is well suited which was also validated with experimental results. Furthermore, the potential of residual gas retention by favorable configurations with a second event already revealed in various publications could be confirmed with respect to exhaust gas temperature increase and engine efficiency.

scholarly journals Effect of Liquid Transparency on Laser-Induced Motion of Drops

2009 ◽  
Vol 131 (8) ◽  
Author(s):  
R. Shukla ◽  
K. A. Sallam
Keyword(s):  
Laser Beam ◽  
Rhodamine 6G ◽  
Marangoni Effect ◽  
Video Camera ◽  
Solid Substrate ◽  
Liquid Drops ◽  
Induced Motion ◽  
532 Nm ◽  
Rhodamine 6G Dye

An experimental investigation of the role of liquid transparency in controlling laser-induced motion of liquid drops is carried out. The study was motivated by application to manipulation of liquid drops over a solid substrate. Droplets with diameters of 1–4 mm were propelled on a hydrophobic substrate using a pulsed-laser beam (532 nm, 10 Hz, 3–12 mJ/pulse) with a 0.9 mm diameter fired parallel to the substrate. The test liquid was distilled water whose transparency was varied by adding different concentrations of Rhodamine 6G dye. Motion of the drops was observed using a video camera. Measurements include direction of motion and the distance traveled before the drops come to rest. The present results show that the direction of the motion depends on the drop transparency; opaque drops moved away from the laser beam, whereas transparent drops moved at small angles toward the laser beam. The motion of both transparent and opaque drops was dominated by thermal Marangoni effect; the motion of opaque drops was due to direct heating by the laser beam, whereas in the case of transparent drops, the laser beam was focused near the rear face of the transparent drops to form a spark that pushed the drops in the opposite direction. Energies lower than 3 mJ were incapable of moving the drops, and energies higher than 12 mJ shattered the drops instead of moving them. A phenomenological model was developed for the drop motion to explain the physics behind the phenomenon.

Laser-Induced Deformation Patterns in Thin Films and Surfaces

1999 ◽  
Vol 121 (2) ◽  
pp. 182-188 ◽  
Author(s):  
Daniel Walgraef
Keyword(s):  
Thin Films ◽  
Laser Irradiation ◽  
Surface Deformation ◽  
Laser Intensity ◽  
Laser Beams ◽  
Experimental Investigations ◽  
Relative Importance ◽  
Periodic Patterns ◽  
One Dimensional ◽  
Deformation Patterns

The coupling between surface deformation and defect motion may be at the origin of deformation patterns in thin films under laser irradiation. We analyze the dynamics of laser-induced vacancy densities and deformation fields and show how it triggers deformational instabilities, in the case of uniform and focused laser irradiation. Pattern selection analysis is performed, through linear, nonlinear, and numerical methods. In irradiation with extended beams, we show that, according to the relative importance of nonlinearities arising from the defect or from the bending dynamics, square, hexagonal or even quasi-periodic patterns are selected. It appears, furthermore, that one-dimensional gratings are always unstable in isotropic systems. In irradiation with focused laser beams, rose deformation patterns, with petal number increasing with laser intensity, naturally arise in this model, in qualitative agreement with experimental observations. These results claim for more systematic and quantitative experimental investigations of deformational pattern formation under laser irradiation.

scholarly journals Mathematical and computer simulation of semiconductor systems of various dimensions and the elements of device structures based on them

2021 ◽  
Vol 57 (4) ◽  
pp. 495-505
Author(s):  
N. A. Poklonski
Keyword(s):  
Chemical Elements ◽  
Three Dimensional ◽  
Experimental Investigations ◽  
State University ◽  
One Dimensional ◽  
The Past ◽  
Silicon Carbon ◽  
Mathematical And Computer Simulation ◽  
Device Structures ◽  
Germanium Silicon

The article, in the form of a minireview, reflects the results of theoretical, and partly experimental investigations of the electrical, optical and magnetic phenomena in three-dimensional, two-dimensional, one-dimensional and zero-dimensional systems and elements of device structures made of germanium, silicon, carbon and other chemical elements carried out at the Faculty of Physics of Belarusian State University over the past 25 years.

scholarly journals Thermal Transport in One-Dimensional Van Der Waals Heterostructures: Effects of Coating Layers on the Thermal Conductivity of Carbon Nanotubes

2020 ◽  
Author(s):  
Penghua Ying ◽  
Jin Zhang ◽  
Yao Du ◽  
Zheng Zhong
Keyword(s):  
Heat Flux ◽  
Thermal Transport ◽  
Van Der Waals ◽  
Thermal Conductance ◽  
One Dimensional ◽  
Interfacial Thermal Conductance ◽  
Quantitative Understanding ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations ◽  
The Individual

In this paper, we conduct a comprehensive investigation on the thermal transport in one-dimensional (1D) van der Waals (vdW) heterostructures by using non-equilibrium molecular dynamics simulations. It is found that the boron nitride nanotube (BNNT) coating can increase the thermal conductance of inner carbon nanotube (CNT) base by 36%, while the molybdenum disulfide nanotube (<a>MSNT</a>) coating can reduce the thermal conductance by 47%. The different effects of BNNT and MSNT coatings on the thermal transport behaviors of 1D vdW heterostructures are explained by the competition mechanism between improved heat flux and increased temperature gradient in 1D vdW heterostructures. By taking CNT@BNNT@MSNT as an example, thermal transport in 1D vdW heterostructures containing three layers is also investigated. It is found that the coaxial BNNT-MSNT coating can significantly reduce the thermal conductance of inner CNT base by 61%, which is even larger than that of an individual MSNT coating. This unexpected reduction in thermal conductance of CNT@BNNT@MSNT can be explained by the suppression of heat flux arising from the possible compression effect, since BNNT-MSNT coating in CNT@BNNT@MSNT can more significantly suppress the vibration of inner CNT when compared to the individual MSNT coating in CNT@MSNT. In addition to the in-plane thermal transport, the interfacial thermal conductance between inner and outer nanotubes in 1D vdW heterostructures is also examined to provide a quantitative understanding of the thermal transport behaviors of1D vdW heterostructures. This work is expected to provide molecular insights into tailoring the heat transport in carbon base 1D vdW heterostructures and thus facilitate their broader applications as thermal interface materials.

scholarly journals A Mathematical Model for Transport in Poroelastic Materials with Variable Volume:Derivation, Lie Symmetry Analysis, and Examples

Symmetry ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 396
Author(s):  
Roman Cherniha ◽  
Joanna Stachowska-Pietka ◽  
Jacek Waniewski
Keyword(s):  
Solute Transport ◽  
Lie Symmetry ◽  
Transport Processes ◽  
Experimental Investigations ◽  
One Dimensional ◽  
Poroelastic Media ◽  
Poroelastic Materials ◽  
Dimensional Version ◽  
The One ◽  
Symmetry Method

Fluid and solute transport in poroelastic media is studied. Mathematical modeling of such transport is a complicated problem because of the volume change of the specimen due to swelling or shrinking and the transport processes are nonlinearly linked. The tensorial character of the variables adds also substantial complication in both theoretical and experimental investigations. The one-dimensional version of the theory is less complex and may serve as an approximation in some problems, and therefore, a one-dimensional (in space) model of fluid and solute transport through a poroelastic medium with variable volume is developed and analyzed. In order to obtain analytical results, the Lie symmetry method is applied. It is shown that the governing equations of the model admit a non-trivial Lie symmetry, which is used for construction of exact solutions. Some examples of the solutions are discussed in detail.

scholarly journals Detection of Delamination in Laminate Wind Turbine Blades Using One-Dimensional Wavelet Analysis of Modal Responses

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Łukasz Doliński ◽  
Marek Krawczuk ◽  
Arkadiusz Żak
Keyword(s):  
Wavelet Transform ◽  
Wind Turbine ◽  
Continuous Wavelet Transform ◽  
Laser Scanning ◽  
Turbine Blades ◽  
Diagnostic Technique ◽  
Experimental Investigations ◽  
Continuous Wavelet ◽  
Wind Turbine Blades ◽  
One Dimensional

This paper demonstrates the effectiveness of a nondestructive diagnostic technique used to determine the location and size of delamination in laminated coatings of wind turbine blades. This is realized based on results of numerical and experimental investigations obtained by the use of the finite element method (FEM) and laser scanning vibrometry (LSV). The proposed method is based on the one-dimensional continuous wavelet transform of vibration parameters of a wind turbine blade. The investigations were conducted for a 1 : 10 scaled-down blade of a 36 m rotor wind turbine. Glass fibres and epoxy resin were used as laminate components. For numerical studies, a simple delamination model was proposed. The results obtained by the authors were used to determine the optimal set of parameters of the continuous wavelet transform. The application of high-quality LSV for experimental measurements allowed determining the optimal conditions of measuring procedures. At the same time the capabilities and limitations, resulting from the nature of the measurement method, were identified. In order to maximize the effectiveness of the detection method, preliminary signal processing was performed. Beside base wavelets also different waveform families were tested. The results obtained by the authors showed that it is possible to identify and localize even relatively small damage.

Special directions in momentum space. III. Practical applications

2015 ◽  
Vol 48 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Grazyna Kontrym-Sznajd
Keyword(s):  
Compton Scattering ◽  
Momentum Space ◽  
Optimal Strategy ◽  
Three Dimensional ◽  
Experimental Investigations ◽  
Experimental Uncertainty ◽  
One Dimensional ◽  
Practical Applications ◽  
Whole Space ◽  
Full Symmetry

This paper complements two previous papers devoted toSpecial directions in momentum space. I. CubicandII. Hexagonal, tetragonal and trigonal symmetries[Kontrym-Sznajd & Samsel-Czekala (2011).J. Appl. Cryst.44, 1246–1254; Kontrym-Sznajd & Samsel-Czekala (2012).J. Appl. Cryst.45, 1254–1260], in which sets of special directions (SDs) were proposed. Such directions, employing the full symmetry of the Brillouin zone, allow for constructing in the whole space anisotropic quantities from their known values along a few directions. SDs also define which spectra, measured in, for example, Compton scattering experiments, are the most efficient for reconstructing three-dimensional densities from their one-dimensional projections. This paper, in which new sets of special directions (SDs) for cubic structures are proposed, is devoted mainly to practical applications of SDs. Taking into account experimental uncertainty, an optimal strategy for experimental investigations is discussed.

Theoretical and experimental investigations of the reflexion of normal shock waves with vibrational relaxation

1967 ◽  
Vol 30 (1) ◽  
pp. 51-64 ◽  
Author(s):  
N. H. Johannesen ◽  
G. A. Bird ◽  
H. K. Zienkiewicz
Keyword(s):  
Shock Wave ◽  
Vibrational Relaxation ◽  
Experimental Investigations ◽  
Rayleigh Line ◽  
Dimensional Problem ◽  
Density Measurements ◽  
Wave Characteristic ◽  
One Dimensional ◽  
The One ◽  
Theoretical Results

The one-dimensional problem of shock-wave reflexion with relaxation is treated numerically by combining the shock-wave, characteristic, and Rayleigh-line equations. The theoretical results are compared with pressure and density measurements in CO2, and the agreement is found to be excellent.

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