Interaction entre écoulement de Stokes et micro-objets (thèse 2016 - 2019)
Publications scientifiques au M2P2
2023
Revaz Chachanidze, Kaili Xie, Jinming Lyu, Marc Jaeger, Marc Leonetti. Breakups of Chitosan microcapsules in extensional flow. Journal of Colloid and Interface Science, 2023, 629, pp.445-454. ⟨10.1016/j.jcis.2022.08.169⟩. ⟨hal-03787637⟩ Plus de détails...
The controlled rupture of a core-shell capsule and the timely release of encapsulated materials are essential steps of the efficient design of such carriers. The mechanical and physico-chemical properties of their shells (or membranes) mainly govern the evolution of such systems under stress and notably the link between the dynamics of rupture and the mechanical properties. This issue is addressed considering weakly cohesive shells made by the interfacial complexation of Chitosan and PFacid in a planar extensional flow. Three regimes are observed, thanks to the two observational planes. Whatever the time of reaction in membrane assembly, there is no rupture in deformation as long as the hydrodynamic stress is below a critical value. At low times of complexation (weak shear elastic modulus), the rupture is reminiscent of the breakup of droplets: a dumbell or a waist. Fluorescent labelling of the membrane shows that this process is governed by continuous thinning of the membrane up to the destabilization. It is likely that the membrane shows a transition from a solid to liquid state. At longer times of complexation, the rupture has a feature of solid-like breakup (breakage) with a discontinuity of the membrane. The maximal internal constraint determined numerically marks the initial location of breakup as shown. The pattern becomes more complex as the elongation rate increases with several points of rupture. A phase diagram in the space parameters of the shear elastic modulus and the hydrodynamic stress is established.
Revaz Chachanidze, Kaili Xie, Jinming Lyu, Marc Jaeger, Marc Leonetti. Breakups of Chitosan microcapsules in extensional flow. Journal of Colloid and Interface Science, 2023, 629, pp.445-454. ⟨10.1016/j.jcis.2022.08.169⟩. ⟨hal-03787637⟩
J Lyu, K Xie, R Chachanidze, A Kahli, Gwenn Boedec, et al.. Dynamics of pearling instability in polymersomes: the role of shear membrane viscosity and spontaneous curvature. Physics of Fluids, American Institute of Physics, 2021, 33 (12), pp.122016. ⟨10.1063/5.0075266⟩. ⟨hal-03597656⟩ Plus de détails...
The stability of copolymer tethers is investigated theoretically. Self-assembly of diblock or triblock copolymers can lead to tubular polymersomes which are known experimentally to undergo shape instability under thermal, chemical and tension stresses. It leads to a periodic modulation of the radius which evolves to assembly-line pearls connected by tiny tethers. We study the contributions of shear surface viscosity and spontaneous curvature and their interplay to understand the pearling instability. The performed linear analysis of stability of this cylinder-to-pearls transition shows that such systems are unstable if the membrane tension is larger than a finite critical value contrary to the Rayleigh-Plateau instability, an already known result or if the spontaneous curvature is in a specific range which depends on membrane tension. For the case of spontaneous curvature-induced shape instability, two dynamical modes are identified. The first one is analog to the tension- induced instability with a marginal mode. Its wavenumber associated with the most un- stable mode decreases continuously to zero as membrane viscosity increases. The second one has a finite range of unstable wavenumbers. The wavenumber of the most unstable mode tends redto be constant as membrane viscosity increases. In this mode, its growth rate becomes independent of the bulk viscosity in the limit of high membrane viscosity and behaves as a pure viscous surface.
J Lyu, K Xie, R Chachanidze, A Kahli, Gwenn Boedec, et al.. Dynamics of pearling instability in polymersomes: the role of shear membrane viscosity and spontaneous curvature. Physics of Fluids, American Institute of Physics, 2021, 33 (12), pp.122016. ⟨10.1063/5.0075266⟩. ⟨hal-03597656⟩
Jinming Lyu, Paul G. Chen, G. Boedec, M. Leonetti, Marc Jaeger. An isogeometric boundary element method for soft particles flowing in microfluidic channels. Computers and Fluids, 2021, 214, pp.104786. ⟨10.1016/j.compfluid.2020.104786⟩. ⟨hal-02476945v2⟩ Plus de détails...
Understanding the flow of deformable particles such as liquid drops, synthetic capsules and vesicles, and biological cells confined in a small channel is essential to a wide range of potential chemical and biomedical engineering applications. Computer simulations of this kind of fluid-structure (mem-brane) interaction in low-Reynolds-number flows raise significant challenges faced by an intricate interplay between flow stresses, complex particles' in-terfacial mechanical properties, and fluidic confinement. Here, we present an isogeometric computational framework by combining the finite-element method (FEM) and boundary-element method (BEM) for an accurate prediction of the deformation and motion of a single soft particle transported in microfluidic channels. The proposed numerical framework is constructed consistently with the isogeometric analysis paradigm; Loop's subdivision elements are used not only for the representation of geometry but also for the membrane mechanics solver (FEM) and the interfacial fluid dynamics solver (BEM). We validate our approach by comparison of the simulation results with highly accurate benchmark solutions to two well-known examples available in the literature, namely a liquid drop with constant surface tension in a circular tube and a capsule with a very thin hyperelastic membrane in a square channel. We show that the numerical method exhibits second-order convergence in both time and space. To further demonstrate the accuracy and long-time numerically stable simulations of the algorithm, we perform hydrodynamic computations of a lipid vesicle with bending stiffness and a red blood cell with a composite membrane in capillaries. The present work offers some possibilities to study the deformation behavior of confining soft particles, especially the particles' shape transition and dynamics and their rheological signature in channel flows.
Jinming Lyu, Paul G. Chen, G. Boedec, M. Leonetti, Marc Jaeger. An isogeometric boundary element method for soft particles flowing in microfluidic channels. Computers and Fluids, 2021, 214, pp.104786. ⟨10.1016/j.compfluid.2020.104786⟩. ⟨hal-02476945v2⟩
J Lyu, K Xie, R Chachanidze, A Kahli, Gwenn Boedec, et al.. Dynamics of pearling instability in polymersomes: the role of shear membrane viscosity and spontaneous curvature. Physics of Fluids, In press, 33 (12), pp.122016. ⟨10.1063/5.0075266⟩. ⟨hal-03467425⟩ Plus de détails...
The stability of copolymer tethers is investigated theoretically. Self-assembly of diblock or triblock copolymers can lead to tubular polymersomes which are known experimentally to undergo shape instability under thermal, chemical and tension stresses. It leads to a periodic modulation of the radius which evolves to assembly-line pearls connected by tiny tethers. We study the contributions of shear surface viscosity and spontaneous curvature and their interplay to understand the pearling instability. The performed linear analysis of stability of this cylinder-to-pearls transition shows that such systems are unstable if the membrane tension is larger than a finite critical value contrary to the Rayleigh-Plateau instability, an already known result or if the spontaneous curvature is in a specific range which depends on membrane tension. For the case of spontaneous curvature-induced shape instability, two dynamical modes are identified. The first one is analog to the tension- induced instability with a marginal mode. Its wavenumber associated with the most un- stable mode decreases continuously to zero as membrane viscosity increases. The second one has a finite range of unstable wavenumbers. The wavenumber of the most unstable mode tends redto be constant as membrane viscosity increases. In this mode, its growth rate becomes independent of the bulk viscosity in the limit of high membrane viscosity and behaves as a pure viscous surface.
J Lyu, K Xie, R Chachanidze, A Kahli, Gwenn Boedec, et al.. Dynamics of pearling instability in polymersomes: the role of shear membrane viscosity and spontaneous curvature. Physics of Fluids, In press, 33 (12), pp.122016. ⟨10.1063/5.0075266⟩. ⟨hal-03467425⟩
Paul G. Chen, J M Lyu, M Jaeger, M. Leonetti. Shape transition and hydrodynamics of vesicles in tube flow. Physical Review Fluids, 2020, 5 (4), pp.043602. ⟨10.1103/PhysRevFluids.5.043602⟩. ⟨hal-02415320v2⟩ Plus de détails...
The steady motion and deformation of a lipid-bilayer vesicle translating through a circular tube in low Reynolds number pressure-driven flow are investigated numerically using an axisymmetric boundary element method. This fluid-structure interaction problem is determined by three dimen-sionless parameters: reduced volume (a measure of the vesicle asphericity), geometric confinement (the ratio of the vesicle effective radius to the tube radius), and capillary number (the ratio of viscous to bending forces). The physical constraints of a vesicle--fixed surface area and enclosed volume when it is confined in a tube--determine critical confinement beyond which it cannot pass through without rupturing its membrane. The simulated results are presented in a wide range of reduced volumes [0.6, 0.98] for different degrees of confinement; the reduced volume of 0.6 mimics red blood cells. We draw a phase diagram of vesicle shapes and propose a shape transition line separating the parachutelike shape region from the bulletlike one in the reduced volume versus confinement phase space. We show that the shape transition marks a change in the behavior of vesicle mobility, especially for highly deflated vesicles. Most importantly, high-resolution simulations make it possible for us to examine the hydrodynamic interaction between the wall boundary and the vesicle surface at conditions of very high confinement, thus providing the limiting behavior of several quantities of interest, such as the thickness of lubrication film, vesicle mobility and its length, and the extra pressure drop due to the presence of the vesicle. This extra pressure drop holds implications for the rheology of dilute vesicle suspensions. Furthermore, we present various correlations and discuss a number of practical applications. The results of this work may serve as a benchmark for future studies and help devise tube-flow experiments.
Paul G. Chen, J M Lyu, M Jaeger, M. Leonetti. Shape transition and hydrodynamics of vesicles in tube flow. Physical Review Fluids, 2020, 5 (4), pp.043602. ⟨10.1103/PhysRevFluids.5.043602⟩. ⟨hal-02415320v2⟩
Jinming Lyu, Paul G. Chen, Gwenn Boedec, Marc Leonetti, Marc Jaeger. Hybrid continuum–coarse-grained modeling of erythrocytes. Comptes Rendus Mécanique, 2018, 346, pp.439-448. ⟨10.1016/j.crme.2018.04.015⟩. ⟨hal-01785429⟩ Plus de détails...
The red blood cell (RBC) membrane is a composite structure, consisting of a phospholipid bilayer and an underlying membrane-associated cytoskeleton. Both continuum and particle-based coarse-grained RBC models make use of a set of vertices connected by edges to represent the RBC membrane, which can be seen as a triangular surface mesh for the former and a spring network for the latter. Here, we present a modeling approach combining an existing continuum vesicle model with a coarse-grained model for the cytoskeleton. Compared to other two-component approaches, our method relies on only one mesh, representing the cytoskeleton, whose velocity in the tangential direction of the membrane may be different from that of the lipid bilayer. The finitely extensible nonlinear elastic (FENE) spring force law in combination with a repulsive force defined as a power function (POW), called FENE-POW, is used to describe the elastic properties of the RBC membrane. The mechanical interaction between the lipid bilayer and the cytoskeleton is explicitly computed and incorporated into the vesicle model. Our model includes the fundamental mechanical properties of the RBC membrane, namely fluidity and bending rigidity of the lipid bilayer, and shear elasticity of the cytoskeleton while maintaining surface-area and volume conservation constraint. We present three simulation examples to demonstrate the effectiveness of this hybrid continuum--coarse-grained model for the study of RBCs in fluid flows.
Jinming Lyu, Paul G. Chen, Gwenn Boedec, Marc Leonetti, Marc Jaeger. Hybrid continuum–coarse-grained modeling of erythrocytes. Comptes Rendus Mécanique, 2018, 346, pp.439-448. ⟨10.1016/j.crme.2018.04.015⟩. ⟨hal-01785429⟩