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Tammisola, Outi, Associate professorORCID iD iconorcid.org/0000-0003-4317-1726
Publications (10 of 70) Show all publications
Agrawal, V., Kulachenko, A., Scapin, N., Tammisola, O. & Brandt, L. (2024). An efficient isogeometric/finite-difference immersed boundary method for the fluid–structure interactions of slender flexible structures. Computer Methods in Applied Mechanics and Engineering, 418, Article ID 116495.
Open this publication in new window or tab >>An efficient isogeometric/finite-difference immersed boundary method for the fluid–structure interactions of slender flexible structures
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2024 (English)In: Computer Methods in Applied Mechanics and Engineering, ISSN 0045-7825, E-ISSN 1879-2138, Vol. 418, article id 116495Article in journal (Refereed) Published
Abstract [en]

In this contribution, we present a robust and efficient computational framework capable of accurately capturing the dynamic motion and large deformation/deflection responses of highly-flexible rods interacting with an incompressible viscous flow. Within the partitioned approach, we adopt separate field solvers to compute the dynamics of the immersed structures and the evolution of the flow field over time, considering finite Reynolds numbers. We employ a geometrically exact, nonlinear Cosserat rod formulation in the context of the isogeometric analysis (IGA) technique to model the elastic responses of each rod in three dimensions (3D). The Navier–Stokes equations are resolved using a pressure projection method on a standard staggered Cartesian grid. The direct-forcing immersed boundary method is utilized for coupling the IGA-based structural solver with the finite-difference fluid solver. In order to fully exploit the accuracy of the IGA technique for FSI simulations, the proposed framework introduces a new procedure that decouples the resolution of the structural domain from the fluid grid. Uniformly distributed Lagrangian markers with density relative to the Eulerian grid are generated to communicate between Lagrangian and Eulerian grids consistently with IGA. We successfully validate the proposed computational framework against two- and three-dimensional FSI benchmarks involving flexible filaments undergoing large deflections/motions in an incompressible flow. We show that six times coarser structural mesh than the flow Eulerian grid delivers accurate results for classic benchmarks, leading to a major gain in computational efficiency. The simultaneous spatial and temporal convergence studies demonstrate the consistent performance of the proposed framework, showing that it conserves the order of the convergence, which is the same as that of the fluid solver.

Place, publisher, year, edition, pages
Elsevier BV, 2024
Keywords
Fluid–structure interactions, Geometrically exact beam model, Immersed-boundary method, Incompressible flows, Isogeometric analysis, Partitioned solvers
National Category
Computational Mathematics Applied Mechanics Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:kth:diva-338863 (URN)10.1016/j.cma.2023.116495 (DOI)001096820100001 ()2-s2.0-85174171313 (Scopus ID)
Note

QC 20231031

Available from: 2023-10-31 Created: 2023-10-31 Last updated: 2023-11-30Bibliographically approved
Tanriverdi, S., Cruz, J., Habibi, S., Amini, K., Costa, M., Lundell, F., . . . Russom, A. (2024). Elasto-inertial focusing and particle migration in high aspect ratio microchannels for high-throughput separation. Microsystems and Nanoengineering, 10(1), Article ID 87.
Open this publication in new window or tab >>Elasto-inertial focusing and particle migration in high aspect ratio microchannels for high-throughput separation
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2024 (English)In: Microsystems and Nanoengineering, E-ISSN 2055-7434, Vol. 10, no 1, article id 87Article in journal (Refereed) Published
Abstract [en]

The combination of flow elasticity and inertia has emerged as a viable tool for focusing and manipulating particles using microfluidics. Although there is considerable interest in the field of elasto-inertial microfluidics owing to its potential applications, research on particle focusing has been mostly limited to low Reynolds numbers (Re<1), and particle migration toward equilibrium positions has not been extensively examined. In this work, we thoroughly studied particle focusing on the dynamic range of flow rates and particle migration using straight microchannels with a single inlet high aspect ratio. We initially explored several parameters that had an impact on particle focusing, such as the particle size, channel dimensions, concentration of viscoelastic fluid, and flow rate. Our experimental work covered a wide range of dimensionless numbers (0.05 < Reynolds number < 85, 1.5 < Weissenberg number < 3800, 5 < Elasticity number < 470) using 3, 5, 7, and 10 µm particles. Our results showed that the particle size played a dominant role, and by tuning the parameters, particle focusing could be achieved at Reynolds numbers ranging from 0.2 (1 µL/min) to 85 (250 µL/min). Furthermore, we numerically and experimentally studied particle migration and reported differential particle migration for high-resolution separations of 5 µm, 7 µm and 10 µm particles in a sheathless flow at a throughput of 150 µL/min. Our work elucidates the complex particle transport in elasto-inertial flows and has great potential for the development of high-throughput and high-resolution particle separation for biomedical and environmental applications. (Figure presented.)

Place, publisher, year, edition, pages
Springer Nature, 2024
National Category
Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:kth:diva-349942 (URN)10.1038/s41378-024-00724-2 (DOI)001253168300001 ()2-s2.0-85196750513 (Scopus ID)
Note

QC 20240705

Available from: 2024-07-03 Created: 2024-07-03 Last updated: 2024-07-05Bibliographically approved
Amini, K., Mishra, A. A., Sivakumar, A. K., Arlov, D., Innings, F., Kádár, R., . . . Lundell, F. (2024). Scaling laws for near-wall flows of thixo-elasto-viscoplastic fluids in a millifluidic channel. Physics of fluids, 36(2), Article ID 023107.
Open this publication in new window or tab >>Scaling laws for near-wall flows of thixo-elasto-viscoplastic fluids in a millifluidic channel
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2024 (English)In: Physics of fluids, ISSN 1070-6631, E-ISSN 1089-7666, Vol. 36, no 2, article id 023107Article in journal (Refereed) Published
Abstract [en]

Thixo-elasto-viscoplastic (TEVP) fluids are very complex fluids. In addition to elasticity and viscoplasticity, they exhibit thixotropy, i.e., time-dependent rheology due to breakdown and recovery of internal structures at different length- and timescales. General and consistent methods for a priori flow prediction of TEVP fluids based on rheological characteristics are yet to be developed. We report a combined study of the rheology and flow of 18 samples of different TEVP fluids (three yogurts and three concentrations of Laponite and Carbopol, respectively, in water in both the unstirred and a stirred state). The rheology is determined both with standard protocols and with an ex situ protocol aiming at reproducing the shear history of the fluid in the flow. Micrometer resolution flow measurements in a millimeter scale rectangular duct are performed with Doppler Optical Coherence Tomography (D-OCT). As expected, the results show the existence of a plug flow region for samples with sufficiently high yield stress. At low flow rates, the plug extends almost all the way to the wall and the extent of the plug decreases not only with increased flow rate but also with increased thixotropy. The ex situ rheology protocol enables estimation of the shear rate and shear stress close to the wall, making it possible to identify two scaling laws that relates four different non-dimensional groups quantifying the key properties wall-shear stress and slip velocity. The scaling laws are suggested as an ansatz for a priori prediction of the near-wall flow of TEVP fluids based on shear flow-curves obtained with a rheometer.

Place, publisher, year, edition, pages
AIP Publishing, 2024
National Category
Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:kth:diva-343664 (URN)10.1063/5.0186668 (DOI)001159051800005 ()2-s2.0-85184810292 (Scopus ID)
Note

QC 20240222

Available from: 2024-02-22 Created: 2024-02-22 Last updated: 2024-04-05Bibliographically approved
Bazesefidpar, K. & Tammisola, O. (2024). The effect of contact angle hysteresis on a droplet in a viscoelastic two-phase system. Physics of fluids, 36(3), Article ID 033119.
Open this publication in new window or tab >>The effect of contact angle hysteresis on a droplet in a viscoelastic two-phase system
2024 (English)In: Physics of fluids, ISSN 1070-6631, E-ISSN 1089-7666, Vol. 36, no 3, article id 033119Article in journal (Refereed) Published
Abstract [en]

We investigate the dynamic behavior of a two-dimensional droplet adhering to a wall in Poiseuille flow at low Reynolds numbers, in a system where one of the phases is viscoelastic represented by a Giesekus model. The Cahn-Hilliard Phase-Field method is used to capture the interface between the two phases. The presence of polymeric molecules alters the viscoelastic drop's deformation over time, categorizing it into two stages before contact line depinning. In the first stage, the viscoelastic droplet deforms faster, while in the second stage, the Newtonian counterpart accelerates and its deformation outpaces the viscoelastic droplet. The deformation of viscoelastic drop is retarded significantly in the second stage with increasing Deborah number De. The viscous bending of viscoelastic drop is enhanced on the receding side for small De, but it is weakened by further increase in De. On the advancing side, the viscous bending is decreased monotonically for Ca<0.25 with a non-monotonic behavior for Ca=0.25. The non-monotonic behavior on the receding side is attributed to the emergence of outward pulling stresses in the vicinity of the receding contact line and the inception of strain-hardening at higher De, while the reduction in the viscous bending at the advancing side is the result of just strain-hardening. Finally, when the medium is viscoelastic, the viscoelasticity suppresses the droplet deformation on both receding and advancing sides, and this effect becomes more pronounced with increasing De. Increasing the Giesekus mobility parameter enhances the weakening effect of viscous bending on the advancing side.

Place, publisher, year, edition, pages
AIP Publishing, 2024
National Category
Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:kth:diva-345928 (URN)10.1063/5.0199348 (DOI)001183702100006 ()2-s2.0-85187785633 (Scopus ID)
Note

QC 20240426

Available from: 2024-04-26 Created: 2024-04-26 Last updated: 2024-04-26Bibliographically approved
Feneuil, B., Iqbal, K. T., Jensen, A., Brandt, L., Tammisola, O. & Carlson, A. (2023). Experimental and numerical investigation of bubble migration in shear flow: Deformability-driven chaining and repulsion. Physical Review Fluids, 8(6), Article ID 063602.
Open this publication in new window or tab >>Experimental and numerical investigation of bubble migration in shear flow: Deformability-driven chaining and repulsion
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2023 (English)In: Physical Review Fluids, E-ISSN 2469-990X, Vol. 8, no 6, article id 063602Article in journal (Refereed) Published
Abstract [en]

We study the interaction-induced migration of bubbles in shear flow and observe that bubbles suspended in elastoviscoplastic emulsions organize into chains aligned in the flow direction, similarly to particles in viscoelastic fluids. To investigate the driving mechanism, we perform experiments and simulations on bubble pairs, using suspending fluids with different rheological properties. First, we notice that, for all fluids, the interaction type depends on the relative position of the bubbles. If they are aligned in the vorticity direction, then they repel, if not, then they attract each other. The simulations show a similar behavior in Newtonian fluids as in viscoelastic and elastoviscoplastic fluids, as long as the capillary number is sufficiently large. This shows that the interaction-related migration of the bubbles is strongly affected by the bubble deformation. We suggest that the cause of migration is the interaction between the heterogeneous pressure fields around the deformed bubbles, due to capillary pressure.

Place, publisher, year, edition, pages
American Physical Society (APS), 2023
National Category
Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:kth:diva-332199 (URN)10.1103/PhysRevFluids.8.063602 (DOI)001019545300003 ()2-s2.0-85164008146 (Scopus ID)
Note

QC 20230721

Available from: 2023-07-21 Created: 2023-07-21 Last updated: 2023-07-21Bibliographically approved
Yada, S., Bazesefidpar, K., Tammisola, O., Amberg, G. & Bagheri, S. (2023). Rapid wetting of shear-thinning fluids. Physical Review Fluids, 8(4), Article ID 043302.
Open this publication in new window or tab >>Rapid wetting of shear-thinning fluids
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2023 (English)In: Physical Review Fluids, E-ISSN 2469-990X, Vol. 8, no 4, article id 043302Article in journal (Refereed) Published
Abstract [en]

Using experiments and numerical simulations, we investigate the spontaneous spread-ing of droplets of aqueous glycerol (Newtonian) and aqueous polymer (shear-thinning) solutions on smooth surfaces. We find that in the first millisecond the spreading of the shear-thinning solutions is identical to the spreading of water, regardless of the polymer concentration. In contrast, aqueous glycerol solutions show a different behavior, namely, a significantly slower spreading rate than water. In the initial rapid spreading phase, the dominating forces that can resist the wetting are inertial forces and contact-line friction. For the glycerol solutions, an increase in glycerol concentration effectively increases the contact-line friction, resulting in increased resistance to wetting. For the polymeric solutions, however, an increase in polymer concentration does not modify contact-line friction. As a consequence, the energy dissipation at the contact line cannot be controlled by varying the amount of additives for shear-thinning fluids. The reduction of the spreading rate of shear-thinning fluids on smooth surfaces in the rapid-wetting regime can only be achieved by increasing solvent viscosity. Our results have implications for phase-change applications where the control of the rapid spreading rate is central, such as anti-icing and soldering.

Place, publisher, year, edition, pages
American Physical Society (APS), 2023
National Category
Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:kth:diva-327173 (URN)10.1103/PhysRevFluids.8.043302 (DOI)000976356900001 ()2-s2.0-85153845237 (Scopus ID)
Note

QC 20230523

Available from: 2023-05-23 Created: 2023-05-23 Last updated: 2023-08-25Bibliographically approved
Bazesefidpar, K., Brandt, L. & Tammisola, O. (2022). A dual resolution phase-field solver for wetting of viscoelastic droplets. International Journal for Numerical Methods in Fluids, 94(9), 1517-1541
Open this publication in new window or tab >>A dual resolution phase-field solver for wetting of viscoelastic droplets
2022 (English)In: International Journal for Numerical Methods in Fluids, ISSN 0271-2091, E-ISSN 1097-0363, Vol. 94, no 9, p. 1517-1541Article in journal (Refereed) Published
Abstract [en]

We present a new and efficient phase-field solver for viscoelastic fluids with moving contact line based on a dual-resolution strategy. The interface between two immiscible fluids is tracked by using the Cahn-Hilliard phase-field model, and the viscoelasticity incorporated into the phase-field framework. The main challenge of this approach is to have enough resolution at the interface to approach the sharp-interface methods. The method presented here addresses this problem by solving the phase field variable on a mesh twice as fine as that used for the velocities, pressure, and polymer-stress constitutive equations. The method is based on second-order finite differences for the discretization of the fully coupled Navier–Stokes, polymeric constitutive, and Cahn–Hilliard equations, and it is implemented in a 2D pencil-like domain decomposition to benefit from existing highly scalable parallel algorithms. An FFT-based solver is used for the Helmholtz and Poisson equations with different global sizes. A splitting method is used to impose the dynamic contact angle boundary conditions in the case of large density and viscosity ratios. The implementation is validated against experimental data and previous numerical studies in 2D and 3D. The results indicate that the dual-resolution approach produces nearly identical results while saving computational time for both Newtonian and viscoelastic flows in 3D. 

Place, publisher, year, edition, pages
Wiley, 2022
Keywords
Cahn–Hilliard equation, dual resolution, dynamic contact angle, viscoelastic fluids, wetting, Constitutive equations, Contact angle, Domain decomposition methods, Navier Stokes equations, Viscoelasticity, Cahn-Hilliard equation, Dual resolutions, International journals, Moving contact lines, Phase fields, Resolution strategy, Vis-coelastic fluids, Visco-elastic fluid, Viscoelastics
National Category
Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:kth:diva-324155 (URN)10.1002/fld.5100 (DOI)000802029900001 ()36247354 (PubMedID)2-s2.0-85130812076 (Scopus ID)
Note

QC 20230227

Available from: 2023-02-27 Created: 2023-02-27 Last updated: 2023-08-21Bibliographically approved
Zhang, W., Shahmardi, A., Choi, K.-s., Tammisola, O., Brandt, L. & Mao, X. (2022). A phase-field method for three-phase flows with icing. Journal of Computational Physics, 458, 111104, Article ID 111104.
Open this publication in new window or tab >>A phase-field method for three-phase flows with icing
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2022 (English)In: Journal of Computational Physics, ISSN 0021-9991, E-ISSN 1090-2716, Vol. 458, p. 111104-, article id 111104Article in journal (Refereed) Published
Abstract [en]

A numerical scheme to simulate three-phase fluid flows with phase change is proposed. By combining the Cahn-Hilliard model for water-air interface, Allen-Cahn equation for ice and fluid and Navier-Stokes equation for momentum, we solve the evolution of the water-air interface and water-ice interface simultaneously, including the volume expansion associated with solidification and due to the density difference between water and ice. Unlike existing schemes assuming a divergence-free flow field, the proposed continuous formulation allows for density changes while ensuring mass conservation. A Poisson equation for the pressure field is derived from mass conservation with constant coefficients, which can efficiently be solved without any pre-conditioning. The results demonstrate that the volume expansion during the ice formation and the subsequent motion of the water-air interface are successfully captured. A parametric study is carried out to examine the dependence of the icing on different physical and numerical parameters. Computations with flow disturbance of different amplitudes demonstrate the robustness of the computational scheme and the uniqueness of the solution over the parameters considered.

Place, publisher, year, edition, pages
Elsevier BV, 2022
Keywords
Phase-field method, Three-phase flows, Solidification, Density change, Poisson equation
National Category
Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:kth:diva-313316 (URN)10.1016/j.jcp.2022.111104 (DOI)000793405100004 ()2-s2.0-85126325320 (Scopus ID)
Funder
EU, Horizon 2020, 864290
Note

QC 20220602

Available from: 2022-06-02 Created: 2022-06-02 Last updated: 2022-11-03Bibliographically approved
Bazesefidpar, K., Brandt, L. & Tammisola, O. (2022). Numerical simulation of the coalescence-induced polymeric droplet jumping on superhydrophobic surfaces. Journal of Non-Newtonian Fluid Mechanics, 307, Article ID 104872.
Open this publication in new window or tab >>Numerical simulation of the coalescence-induced polymeric droplet jumping on superhydrophobic surfaces
2022 (English)In: Journal of Non-Newtonian Fluid Mechanics, ISSN 0377-0257, E-ISSN 1873-2631, Vol. 307, article id 104872Article in journal (Refereed) Published
Abstract [en]

Self-propelled jumping of two polymeric droplets on superhydrophobic surfaces is investigated by three-dimensional direct numerical simulations. Two identical droplets of a viscoelastic fluid slide, meet and coalesce on a surface with contact angle 180 degrees. The droplets are modelled by the Giesekus constitutive equation, introducing both viscoelasticity and a shear-thinning effects. The Cahn-Hilliard Phase-Field method is used to capture the droplet interface. The simulations capture the spontaneous coalescence and jumping of the droplets. The effect of elasticity and shear-thinning on the coalescence and jumping is investigated at capillary-inertial and viscous regimes. The results reveal that the elasticity of the droplet changes the known capillary-inertial velocity scaling of the Newtonian drops at large Ohnesorge numbers; the resulting viscoelastic droplet jumps from the surface at larger Ohnesorge numbers than a Newtonian drop, when elasticity amplifies visible shape oscillations of the merged droplet. The numerical results show that polymer chains are stretched during the coalescence and prior to the departure of two drops, and the resulting elastic stresses at the interface induce the jumping of the liquid out of the surface. This study shows that viscoelasticity, typical of many biological and industrial applications, affects the droplet behaviour on superhydrophobic and self-cleaning surfaces.

Place, publisher, year, edition, pages
Elsevier BV, 2022
Keywords
Coalescence-induced droplet jumping, Viscoelasticity, Jumping velocity, Superhydrophobic surface, Diffuse-interface method
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-320492 (URN)10.1016/j.jnnfm.2022.104872 (DOI)000861808200003 ()2-s2.0-85134604501 (Scopus ID)
Note

QC 20230825

Available from: 2022-10-26 Created: 2022-10-26 Last updated: 2023-08-25Bibliographically approved
Geetha Balasubramanian, A., Vinuesa, R. & Tammisola, O. (2022). Prediction of wall-bounded turbulence in a viscoelastic channel flow using convolutional neural networks. In: Prediction of wall-bounded turbulence in a viscoelastic channel flow using convolutional neural networks: . Paper presented at Joint ERCOFTAC/EU-CTFF European Drag Reduction and Flow Control Meeting – EDRFCM 2022, September 6–9, 2022, Paris, France.
Open this publication in new window or tab >>Prediction of wall-bounded turbulence in a viscoelastic channel flow using convolutional neural networks
2022 (English)In: Prediction of wall-bounded turbulence in a viscoelastic channel flow using convolutional neural networks, 2022Conference paper, Oral presentation only (Other academic)
Abstract [en]

Turbulent flow of purely viscoelastic fluids has gained attention in the drag-reduction and flow control communities since a tiny amount of polymer has proven efficient in reducing friction drag in pipe flows. Drag reduction by polymers (elasticity) is related to their ability to modify coherent structures in wall-bounded turbulence. When it comes to practical flows of interest, numerical simulations of such flows become challenging due to the associated computational cost of capturing the multiple physical mechanisms that drive the flow. On the other hand, experimental investigations of drag reduction in viscoelastic flows are limited by the near-wall measurements and the capability of the experimental techniques to accurately quantify the flow, without disturbing it. A complete description of viscoelastic turbulence would require the characterization of both velocity and polymeric stresses. However, the polymer deformation cannot be accessed directly from the experiments. Hence, in the objective of the present study, the idea of non-intrusive sensing has been applied to viscoelastic channel flow to predict the velocity fluctuations and polymeric stress components near the wall using the quantities measured at the wall. To this aim, the convolutional neural network (CNN) models are trained to predict the two-dimensional velocity fluctuation and polymeric shear stress fluctuation and elongation fields at different wall-normal distances in a viscoelastic channel flow. The present work would highlight the capability of a data-driven approach to model turbulence in complex fluid flows and in addition also finds useful applications in experimental settings.

Keywords
Turbulence, Machine learning, Viscoelastic flow
National Category
Mechanical Engineering Fluid Mechanics and Acoustics
Research subject
Engineering Mechanics
Identifiers
urn:nbn:se:kth:diva-324736 (URN)
Conference
Joint ERCOFTAC/EU-CTFF European Drag Reduction and Flow Control Meeting – EDRFCM 2022, September 6–9, 2022, Paris, France
Note

QC 20230322

Available from: 2023-03-14 Created: 2023-03-14 Last updated: 2024-03-18Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-4317-1726

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