Microstructure – Fluid Dynamics

The research of the group focuses on interfacial instability, wetting, and phase transitions in alloys and polymer solutions, where both fluid dynamics and diffusion are present and coupled.

Contact person: Dr.-Ing. Fei Wang, Dr. Haodong Zhang

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Research

By employing the phase-field method, the research of the group concentrates on the microstructural evolution process, where both fluid dynamics and diffusion are present. Two different phase-field approaches, namely Cahn-Hilliard and Allen-Cahn models, coupled with the Navier-Stokes equations, are adopted to model particular physical problems. The following research areas are considered.

Wetting

Different kinds of wetting phenomena are considered, such as reactive wetting in the process of soldering, inertial wetting on patterned structures, and wetting transitions in dependence of the temperature/composition.

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Wetting on a structured surface
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Interface instability, using the example of a chain of droplets on the tap (photo and simulation)

Interfacial instability

When we open a water tap, the water trickles down and breaks apart into a chain of droplets, which is a typical interfacial instability in fluid dynamics. Similar to this, a thin liquid film may also break up into droplets or liquid rings. The problem becomes more complex if the liquid phase is in contact with a solid phase, where the wetting mechanism has to be considered.  For this topic, we scrutinize the interfacial evolutions and instabilities by developing theoretical models and performing numerical simulations based on the phase-field methods.

Formation of porous structures from polymer solutions

Porous structures can be formed from polymer solutions via spinodal decomposition. During the structural formation process, two stages are assumed: At the first stage, the solution is considered to be a liquid phase, where the surface tension and phase transition dominate the microstructural evolution. At the second stage, gelation takes place, where the droplets resulting from the phase separation are solid-like. Here, viscoelastic properties have to be taken into account. We aim to develop a thermodynamically consistent phase-field model for this structure formation process.

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Simulation of the structure formation process of a porous structure from a polymer solution
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Visualization of a simulation of solidification

Solidification

We adopt the phase-field model to study phase transition, such as dendrite growth, monotectic reaction, peritectic reaction, and eutectic reaction, where diffusion and convection are involved.

Rigid body motion

In contrast to the soft matter particles with finite deformations in the formation process of porous structures, we here consider rigid body particles, where the deformation is zero. For this topic, a phase-field model is currently being developed.

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Simulation of rigid body motion in a flowing fluid
Team
Name Function
Dargahi Noubary, Kaveh Research assistant
Farzaneh Kalourazi, Saeideh Research Assistant
Zhang, Haodong Research assistant
3 additional persons visible within KIT only.

Publications


2024
Chemo-elasto-electro free energy of non-uniform system in the diffuse interface context
Cai, Y.; Wang, F.; Zhang, H.; Nestler, B.
2024. Journal of Physics: Condensed Matter, 36, Article no: 495702. doi:10.1088/1361-648X/ad7660
Exploration of contact angle hysteresis mechanisms: From microscopic to macroscopic
Zhang, H.; Zhang, H.; Wang, F.; Nestler, B.
2024. The Journal of Chemical Physics, 161 (19), Art.-Nr.: 194705. doi:10.1063/5.0232287
Wetting phenomena of droplets and gas bubbles: Contact angle hysteresis based on varying liquid–solid and solid–gas interfacial tensions
Aurbach, F.; Wang, F.; Nestler, B.
2024. The Journal of Chemical Physics, 161 (16), Art.-Nr. : 164708
Misoriented lamellar microstructures in Mo‐Si‐Ti alloy due to asymmetrical nucleation distance and interfacial energies: A phase‐field analysis
Cai, Y.; Wang, F.; Nestler, B.
2024. Advanced Engineering Materials, 26 (17), 2302082. doi:10.1002/adem.202302082
Electric-field induced phase separation and dielectric breakdown in leaky dielectric mixtures: Thermodynamics and kinetics
Zhang, H.; Wang, F.; Nestler, B.
2024. The Journal of Chemical Physics, 161 (4). doi:10.1063/5.0203527
Compressible and immiscible fluids with arbitrary density ratio
Wang, F.; Nestler, B.
2024. arxiv. doi:10.5445/IR/1000176219
Wetting Effect Induced Depletion and Adsorption Layers: Diffuse Interface Perspective
Zhang, H.; Zhang, H.; Wang, F.; Nestler, B.
2024. ChemPhysChem, Art.-Nr.: 202400086. doi:10.1002/cphc.202400086
Multi-component electro-hydro-thermodynamic model with phase-field method. I. Dielectric
Zhang, H.; Wang, F.; Nestler, B.
2024. Journal of Computational Physics, 505, 112907. doi:10.1016/j.jcp.2024.112907
Wetting and Contact-Angle Hysteresis: Density Asymmetry and van der Waals Force
Wang, F.; Nestler, B.
2024. Physical Review Letters, 132 (12), Art.-Nr.: 126202. doi:10.1103/PhysRevLett.132.126202
Evolution dynamics of thin liquid structures investigated using a phase-field model
Wu, Y.; Wang, F.; Zheng, S.; Nestler, B.
2024. Soft Matter, 20 (7), 1523–1542. doi:10.1039/D3SM01553J
Brownian motion of droplets induced by thermal noise
Zhang, H.; Wang, F.; Ratke, L.; Nestler, B.
2024. Physical Review E, 109 (2), 024208. doi:10.1103/PhysRevE.109.024208
Wetting Behavior of Inkjet-Printed Electronic Inks on Patterned Substrates
Arya, P.; Wu, Y.; Wang, F.; Wang, Z.; Cadilha Marques, G.; Levkin, P. A.; Nestler, B.; Aghassi-Hagmann, J.
2024. Langmuir, 40 (10), 5162–5173. doi:10.1021/acs.langmuir.3c03297
Digital twin of a droplet microarray platform: Evaporation behavior for multiple droplets on patterned chips for cell culture
Wu, Y.; Urrutia Gómez, J. E.; Zhang, H.; Wang, F.; Levkin, P. A.; Popova, A. A.; Nestler, B.
2024. Droplet, 3 (1), Art.-Nr. e94. doi:10.1002/dro2.94
2023
Effect of wall free energy formulation on the wetting phenomenon: Conservative Allen–Cahn model
Zhang, H.; Wu, Y.; Wang, F.; Nestler, B.
2023. The Journal of Chemical Physics, 159 (16). doi:10.1063/5.0168394
Phase-field investigation on the microstructural evolution of eutectic transformation and four-phase reaction in Mo-Si-Ti system
Cai, Y.; Wang, F.; Czerny, A.; Seifert, H. J.; Nestler, B.
2023. Acta Materialia, 258, 119178
Phase-field investigation on the microstructural evolution of eutectic transformation and four-phase reaction in Mo-Si-Ti system
Cai, Y.; Wang, F.; Czerny, A.; Seifert, H. J.; Nestler, B.
2023. Acta Materialia, 258, Art.-Nr.: 119178. doi:10.1016/j.actamat.2023.119178
A thermodynamically consistent diffuse interface model for the wetting phenomenon of miscible and immiscible ternary fluids
Wang, F.; Zhang, H.; Wu, Y.; Nestler, B.
2023. Journal of Fluid Mechanics, 970, Art.Nr.: A17. doi:10.1017/jfm.2023.561
A new technical pathway for extracting high accuracy surface deformation information in coal mining areas using UAV LiDAR data: An example from the Yushen mining area in western China
Yang, Q.; Tang, F.; Wang, F.; Tang, J.; Fan, Z.; Ma, T.; Su, Y.; Xue, J.
2023. Measurement: Journal of the International Measurement Confederation, 218, Art.Nr.: 113220. doi:10.1016/j.measurement.2023.113220
Wetting Effect on Patterned Substrates
Wang, F.; Wu, Y.; Nestler, B.
2023. Advanced Materials, 35 (25), Art.-Nr.: 2210745. doi:10.1002/adma.202210745
Line tension of sessile droplets: Thermodynamic considerations
Zhang, H.; Wang, F.; Nestler, B.
2023. Physical review / B, 108 (5), Art.-Nr.: 054121. doi:10.1103/PhysRevE.108.054121
State-of-the-art review of porous polymer membrane formation characterization—How numerical and experimental approaches dovetail to drive innovation
Bohr, S. J.; Wang, F.; Metze, M.; Vukušić, J. L.; Sapalidis, A.; Ulbricht, M.; Nestler, B.; Barbe, S.
2023. Frontiers in Sustainability, 4, 1093911
State-of-the-art review of porous polymer membrane formation characterization—How numerical and experimental approaches dovetail to drive innovation
Bohr, S. J.; Wang, F.; Metze, M.; Vukušić, J. L.; Sapalidis, A.; Ulbricht, M.; Nestler, B.; Barbe, S.
2023. Frontiers in Sustainability, 4, Art.-Nr.: 1093911. doi:10.3389/frsus.2023.1093911
Automated high-throughput image processing as part of the screening platform for personalized oncology
Schilling, M. P.; El Khaled El Faraj, R.; Urrutia Gómez, J. E.; Sonnentag, S. J.; Wang, F.; Nestler, B.; Orian-Rousseau, V.; Popova, A. A.; Levkin, P. A.; Reischl, M.
2023. Scientific Reports, 13, Article no: 5107. doi:10.1038/s41598-023-32144-z
Nanoliter Scale Parallel Liquid–Liquid Extraction for High‐Throughput Purification on a Droplet Microarray
Wiedmann, J. J.; Demirdögen, Y. N.; Schmidt, S.; Kuzina, M. A.; Wu, Y.; Wang, F.; Nestler, B.; Hopf, C.; Levkin, P. A.
2023. Small, 19 (9), Art.Nr. 2204512. doi:10.1002/smll.202204512
2022
Phase-field simulation for the formation of porous microstructures due to phase separation in polymer solutions on substrates with different wettabilities
Farzaneh Kalourazi, S.; Wang, F.; Zhang, H.; Selzer, M.; Nestler, B.
2022. Journal of Physics: Condensed Matter, 34 (44), Art.-Nr.: 444003. doi:10.1088/1361-648X/ac8b4d
Janus Droplet Formation via Thermally Induced Phase Separation: A Numerical Model with Diffusion and Convection
Zhang, H.; Wang, F.; Nestler, B.
2022. Langmuir, 38 (22), 6882–6895. doi:10.1021/acs.langmuir.2c00308
Capillary adsorption of droplets into a funnel-like structure
Wu, Y.; Wang, F.; Huang, W.; Selzer, M.; Nestler, B.
2022. Physical Review Fluids, 7 (5), Art.-Nr.: 054004. doi:10.1103/PhysRevFluids.7.054004
A Two-Dimensional Phase-Field Investigation on Unidirectionally Solidified Tip-Splitting Microstructures
Laxmipathy, V. P.; Wang, F.; Selzer, M.; Nestler, B.
2022. Metals, 12 (3), Art.-Nr.: 376. doi:10.3390/met12030376
Equilibrium droplet shapes on chemically patterned surfaces: theoretical calculation, phase-field simulation, and experiments
Wu, Y.; Kuzina, M.; Wang, F.; Reischl, M.; Selzer, M.; Nestler, B.; Levkin, P. A.
2022. Journal of Colloid and Interface Science, 606, 1077–1086. doi:10.1016/j.jcis.2021.08.029
2021
3D printing of inherently nanoporous polymers via polymerization-induced phase separation
Dong, Z.; Cui, H.; Zhang, H.; Wang, F.; Zhan, X.; Mayer, F.; Nestler, B.; Wegener, M.; Levkin, P. A.
2021. Nature Communications, 12 (1), Art:nr. 247. doi:10.1038/s41467-020-20498-1
Phase-field formulation of a fictitious domain method for particulate flows interacting with complex and evolving geometries
Reder, M.; Schneider, D.; Wang, F.; Daubner, S.; Nestler, B.
2021. International Journal for Numerical Methods in Fluids, 93 (8), 2486–2507. doi:10.1002/fld.4984
Correction to: A phase-field study on polymerization-induced phase separation occasioned by diffusion and capillary flow—a mechanism for the formation of porous microstructures in membranes
Wang, F.; Ratke, L.; Zhang, H.; Altschuh, P.; Nestler, B.
2021. Journal of sol gel science and technology, 99 (1), 273. doi:10.1007/s10971-021-05565-3
Phase-field simulations of grain boundary grooving under diffusive-convective conditions
Laxmipathy, V. P.; Wang, F.; Selzer, M.; Nestler, B.
2021. Acta materialia, 204, Art.-Nr.: 116497. doi:10.1016/j.actamat.2020.116497
Phase-Field Modeling of Multiple Emulsions Via Spinodal Decomposition
Zhang, H.; Wu, Y.; Wang, F.; Guo, F.; Nestler, B.
2021. Langmuir, 37 (17), 5275–5281. doi:10.1021/acs.langmuir.1c00275
Liquid Wells as Self-Healing, Functional Analogues to Solid Vessels
Scheiger, J. M.; Kuzina, M. A.; Eigenbrod, M.; Wu, Y.; Wang, F.; Heißler, S.; Hardt, S.; Nestler, B.; Levkin, P. A.
2021. Advanced Materials, 33 (23), Art.-Nr.: 2100117. doi:10.1002/adma.202100117
Multiphase-field model for surface diffusion and attachment kinetics in the grand-potential framework
Hoffrogge, P. W.; Mukherjee, A.; Nani, E. S.; Amos, P. G. K.; Wang, F.; Schneider, D.; Nestler, B.
2021. Physical review / E, 103 (3), Article no: 033307. doi:10.1103/PhysRevE.103.033307
Wetting transition and phase separation on flat substrates and in porous structures
Wang, F.; Nestler, B.
2021. Journal of Chemical Physics, 154 (9), Art.-Nr.: 094704. doi:10.1063/5.0044914
2020
Microstructural transition in monotectic alloys: A phase-field study
Laxmipathy, V. P.; Wang, F.; Selzer, M.; Nestler, B.
2020. International journal of heat and mass transfer, 159, Art.-Nr. 120096. doi:10.1016/j.ijheatmasstransfer.2020.120096
How do chemical patterns affect equilibrium droplet shapes?
Wu, Y.; Wang, F.; Ma, S.; Selzer, M.; Nestler, B.
2020. Soft matter, 16 (26), 6115–6127. doi:10.1039/d0sm00196a
A phase-field study on polymerization-induced phase separation occasioned by diffusion and capillary flow - a mechanism for the formation of porous microstructures in membranes
Wang, F.; Ratke, L.; Zhang, H.; Altschuh, P.; Nestler, B.
2020. Journal of sol gel science and technology, 94 (1), 356–374. doi:10.1007/s10971-020-05238-7
2019
Influence of melt convection on the morphological evolution of seaweed structures: Insights from phase-field simulations
Pavan Laxmipathy, V.; Wang, F.; Selzer, M.; Nestler, B.; Ankit, K.
2019. Computational materials science, 170, Art.-Nr. 109196. doi:10.1016/j.commatsci.2019.109196
Progress Report on Phase Separation in Polymer Solutions
Wang, F.; Altschuh, P.; Ratke, L.; Zhang, H.; Selzer, M.; Nestler, B.
2019. Advanced materials, 31 (26), Art.Nr. 1806733. doi:10.1002/adma.201806733
Investigation of Equilibrium Droplet Shapes on Chemically Striped Patterned Surfaces Using Phase-Field Method
Wu, Y.; Wang, F.; Selzer, M.; Nestler, B.
2019. Langmuir, 35 (25), 8500–8516. doi:10.1021/acs.langmuir.9b01362
Phase-field investigation on the growth orientation angle of aluminum carbide with a needle-like structure at the surface of graphite particles
Cai, Y.; Wang, F.; Selzer, M.; Nestler, B.
2019. Modelling and simulation in materials science and engineering, 27 (6), Art.-Nr.: 065010. doi:10.1088/1361-651X/ab2351
Phase-field study on the growth of magnesium silicide occasioned by reactive diffusion on the surface of Si-foams
Wang, F.; Altschuh, P.; Matz, A. M.; Heimann, J.; Matz, B. S.; Nestler, B.; Jost, N.
2019. Acta materialia, 170, 138–154. doi:10.1016/j.actamat.2019.03.008
2018
Phase-field modeling of reactive wetting and growth of the intermetallic Al2 Au phase in the Al-Au system
Wang, F.; Reiter, A.; Kellner, M.; Brillo, J.; Selzer, M.; Nestler, B.
2018. Acta materialia, 146, 106–118. doi:10.1016/j.actamat.2017.12.015
Phase-field study of surface irregularities of a cathode particle during intercalation
Santoki, J.; Schneider, D.; Selzer, M.; Wang, F.; Kamlah, M.; Nestler, B.
2018. Modelling and simulation in materials science and engineering, 26 (6), 065013. doi:10.1088/1361-651X/aad20a
2017
Numerical and experimental investigations on the growth of the intermetallic Mg₂Si phase in Mg infiltrated Si-foams
Wang, F.; Matz, A. M.; Tschukin, O.; Heimann, J.; Mocker, B. S.; Nestler, B.; Jost, N.
2017. Advanced engineering materials, 19 (10), Art.Nr. 1700063. doi:10.1002/adem.201700063
Effect of capillarity on the breakup of liquid jets, interfacial wave and motion of droplets in immiscible liquids. PhD dissertation
Wang, F.
2017. Karlsruher Institut für Technologie (KIT). doi:10.5445/IR/1000071294
2016
Detachment of nanowires driven by capillarity
Wang, F.; Nestler, B.
2016. Scripta materialia, 113, 167–170. doi:10.1016/j.scriptamat.2015.11.002
2015
A phase-field study on the formation of the intermetallic AlAu phase in the Al-Au system
Wang, F.; Nestler, B.
2015. Acta materialia, 95 (2), 65–73. doi:10.1016/j.actamat.2015.05.002
Underdamped capillary wave caused by solutal Marangoni convection in immiscible liquids
Wang, F.; Ben Said, M.; Selzer, M.; Nestler, B.
2015. Journal of materials science, 51 (4), 1820–1828. doi:10.1007/s10853-015-9600-1
Experimental and Numerical Investigation on the Phase Separation Affected by Cooling Rates and Marangoni Convection in Cu-Cr Alloys
Wang, F.; Klinski-Wetzel, K. von; Mukherjee, R.; Nestler, B.; Heilmaier, M.
2015. Metallurgical and materials transactions / A, 46 (4), 1756–1766. doi:10.1007/s11661-015-2745-3
On the motion of droplets driven by solutal Marangoni convection in alloy systems with a miscibility gap
Wang, F.; Selzer, M.; Nestler, B.
2015. Physica D: Nonlinear Phenomena, 307, 82–96. doi:10.1016/j.physd.2015.06.001
2014
Numerical study on solutal Marangoni instability in finite systems with a miscibility gap
Wang, F.; Mukherjee, R.; Selzer, M.; Nestler, B.
2014. Physics of fluids, 26 (12), Art.Nr. 1.4902355. doi:10.1063/1.4902355