A numerical method for the calculation of drag and lift of a deformable droplet in shear flow

Suh, Youngho; Lee, Chang‐Hoon

doi:10.1016/j.jcp.2013.01.034

Cited by 14 publications

(4 citation statements)

References 29 publications

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“…To address such a circumstance, we introduce a feedback forcing function developed by Suh and Lee. 29 The formulation of the feedback forces 29 acting in the y and z directions per unit mass is modified to be…”

Section: Force Measurementmentioning

confidence: 99%

“…The feedback forces adjust themselves dynamically to bring the droplets to the prescribed position. The coefficients used in the present paper are set to be 10, 5, and 5 according to the stability analysis of Suh and Lee 29 and the time-step in our simulations. By adding the feedback forces as source terms to the momentum equation, the droplet can be driven to y c or z c in the y or z directions after achieving an equilibrium state.…”

Section: Force Measurementmentioning

confidence: 99%

See 1 more Smart Citation

Inertial migration of deformable droplets in a microchannel

Chen

Xue

Zhang³

et al. 2014

Physics of Fluids

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The microfluidic inertial effect is an effective way of focusing and sorting droplets suspended in a carrier fluid in microchannels. To understand the flow dynamics of microscale droplet migration, we conduct numerical simulations on the droplet motion and deformation in a straight microchannel. The results are compared with preliminary experiments and theoretical analysis. In contrast to most existing literature, the present simulations are three-dimensional and full length in the streamwise direction and consider the confinement effects for a rectangular cross section. To thoroughly examine the effect of the velocity distribution, the release positions of single droplets are varied in a quarter of the channel cross section based on the geometrical symmetries. The migration dynamics and equilibrium positions of the droplets are obtained for different fluid velocities and droplet sizes. Droplets with diameters larger than half of the channel height migrate to the centerline in the height direction and two equilibrium positions are observed between the centerline and the wall in the width direction. In addition to the well-known Segré-Silberberg equilibrium positions, new equilibrium positions closer to the centerline are observed. This finding is validated by preliminary experiments that are designed to introduce droplets at different initial lateral positions. Small droplets also migrate to two equilibrium positions in the quarter of the channel cross section, but the coordinates in the width direction are between the centerline and the wall. The equilibrium positions move toward the centerlines with increasing Reynolds number due to increasing deformations of the droplets. The distributions of the lift forces, angular velocities, and the deformation parameters of droplets along the two confinement direction are investigated in detail. Comparisons are made with theoretical predictions to determine the fundamentals of droplet migration in microchannels. In addition, existence of the inner equilibrium position is linked to the quartic velocity distribution in the width direction through a simple model for the slip angular velocities of droplets.

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Section: Force Measurementmentioning

confidence: 99%

Section: Force Measurementmentioning

confidence: 99%

Inertial migration of deformable droplets in a microchannel

Chen

Xue

Zhang³

et al. 2014

Physics of Fluids

View full text Add to dashboard Cite

show abstract

“…Similarly, Fig. 3b shows that the adaptive methods can successfully predict the drag force in comparison to spherical shape [64] and deformable spherical shape [65,66]. different models, including constant temperature model [68], uniform temperature model [69], non-uniform temperature distribution [70] and non-uniform temperature distribution with boundary layer [71,72], to calculate the droplet evaporation rate and its temperature distribution.…”

Section: Dropletsmentioning

confidence: 99%

Predicting the effects of environmental parameters on the spatio-temporal distribution of the droplets carrying coronavirus in public transport – A machine learning approach

Mesgarpour

Abad

Alizadeh

et al. 2022

Chemical Engineering Journal

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“…This may be due to the effect of the aerodynamic drag, that affects significantly this class of small droplets. Under this effect, the unstable droplet shape oscillates due to the surface tension that tends to restore its round shape, hence a periodic, elliptic deformation [10]. The biggest, elongate elliptical droplets (D > 100 µm) may proceed from ligament parts (see Figure 8a).…”

Section: Distribution Of Droplet Shapesmentioning

confidence: 99%

Characterization of Liquid Impinging Jet Injector Sprays for Bi-Propellant Space Propulsion: Comparison of PDI and High-Magnification Shadowgraphy

Boust

Michalski

Claverie

et al. 2017

Proceedings ILASS–Europe 2017. 28th Conference on Liquid Atomization and Spray Systems

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Impinging jet sprays are investigated in the reference case of like-doublet injector, for application to bi-propellant combustion. Green propellants are considered, namely ethanol as a fuel and hydrogen peroxide as an oxidizer, that is well represented by water. This study reports original comparisons between standard spray characterization (PDI) and high-magnification shadowgraphy of the spray (2.5 x 3.2 mm, 2.5 µm per pixel) based on short laser backlight illumination (5 ns). Shadowgraphy images describe accurately the inner spray structure and provide the size and velocity of droplets. This diagnostic is used to analyse the influence of jet momentum (driven by injection pressure) on impinging jet atomization, as well as the evolution of spray topology, drop size distribution and average diameter along the spray centreline. The application of shadowgraphy to the dense region of water and ethanol sprays shows the different atomization behaviour of these two fluids with respect to their surface tension. Elliptical droplets are characterized inside the spray, which confirms the interest of a direct visualization of droplets in such dense sprays.

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A numerical method for the calculation of drag and lift of a deformable droplet in shear flow

Cited by 14 publications

References 29 publications

Inertial migration of deformable droplets in a microchannel

Inertial migration of deformable droplets in a microchannel

Predicting the effects of environmental parameters on the spatio-temporal distribution of the droplets carrying coronavirus in public transport – A machine learning approach

Characterization of Liquid Impinging Jet Injector Sprays for Bi-Propellant Space Propulsion: Comparison of PDI and High-Magnification Shadowgraphy

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