0000000000590368

AUTHOR

Aaron Brunk

0000-0003-4987-2398

showing 3 related works from this author

Systematic derivation of hydrodynamic equations for viscoelastic phase separation

2021

(abridged) We present a detailed derivation of a simple hydrodynamic two-fluid model, which aims at the description of the phase separation of non-entangled polymer solutions, where viscoelastic effects play a role. It is directly based upon the coarse-graining of a well-defined molecular model, such that all degrees of freedom have a clear and unambiguous molecular interpretation. The considerations are based upon a free-energy functional, and the dynamics is split into a conservative and a dissipative part, where the latter satisfies the Onsager relations and the Second Law of thermodynamics. The model is therefore fully consistent with both equilibrium and non-equilibrium thermodynamics.…

PhysicsStatistical Mechanics (cond-mat.stat-mech)media_common.quotation_subjectConstitutive equationScalar (physics)Degrees of freedom (physics and chemistry)Four-vectorEquations of motionFOS: Physical sciencesSecond law of thermodynamicsCondensed Matter - Soft Condensed MatterCondensed Matter PhysicsClassical mechanicsDissipative systemSoft Condensed Matter (cond-mat.soft)General Materials ScienceVector fieldCondensed Matter - Statistical Mechanicsmedia_common
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Analysis of a viscoelastic phase separation model

2020

A new model for viscoelastic phase separation is proposed, based on a systematically derived conservative two-fluid model. Dissipative effects are included by phenomenological viscoelastic terms. By construction, the model is consistent with the second law of thermodynamics, and we study well-posedness of the model, i.e., existence of weak solutions, a weak-strong uniqueness principle, and stability with respect to perturbations, which are proven by means of relative energy estimates. A good qualitative agreement with mesoscopic simulations is observed in numerical tests.

media_common.quotation_subjectFOS: Physical sciencesSecond law of thermodynamics02 engineering and technologySpace (mathematics)01 natural sciencesStability (probability)ViscoelasticityMathematics - Analysis of PDEs0103 physical sciencesFOS: MathematicsGeneral Materials ScienceStatistical physicsUniqueness010306 general physicsMathematical Physicsmedia_commonPhysicsMesoscopic physicsDynamic structure factorMathematical Physics (math-ph)021001 nanoscience & nanotechnologyCondensed Matter PhysicsDissipative system0210 nano-technologyAnalysis of PDEs (math.AP)
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Chemotaxis and Haptotaxis on Cellular Level

2018

Chemotaxis and haptotaxis have been a main theme in the macroscopic study of bacterial and cellular motility. In this work, we use a successful model that describes cellular motility and investigate the influence these processes have on the shape and motility of fast migrating cells. We note that, despite the biological and modelling differences of chemotaxis and haptotaxis, the cells exhibit many similarities in their migration. In particular, after an initial adjustment phase, the cells obtain a stable shape, similar in both cases, and move with constant velocity.

Constant velocityMotilityChemotaxisCellular motilityBiologyCellular levelLamellipodiumHaptotaxisCell biology
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