marhorn

• Badia, Santiago; Hornkjøl, Martin; Khan, Arbaz; Mardal, Kent-Andre; Martín, Alberto F. & Ruiz-Baier, Ricardo (2024). Efficient and reliable divergence-conforming methods for an elasticity-poroelasticity interface problem. Computers and Mathematics with Applications. ISSN 0898-1221. 157, s. 173–194. doi: 10.1016/j.camwa.2023.12.038. Fulltekst i vitenarkiv Vis sammendrag

  We present a finite element discretization to model the interaction between a poroelastic structure and an elastic medium. The consolidation problem considers fully coupled deformations across an interface, ensuring continuity of displacement and total traction, as well as no-flux for the fluid phase. Our formulation of the poroelasticity equations incorporates displacement, fluid pressure, and total pressure, while the elasticity equations adopt a displacement-pressure formulation. Notably, the transmission conditions at the interface are enforced without the need for Lagrange multipliers. We demonstrate the stability and convergence of the divergence-conforming finite element method across various polynomial degrees. The a priori error bounds remain robust, even when considering large variations in intricate model parameters such as Lamé constants, permeability, and storativity coefficient. To enhance computational efficiency and reliability, we develop residual-based a posteriori error estimators that are independent of the aforementioned coefficients. Additionally, we devise parameter-robust and optimal block diagonal preconditioners. Through numerical examples, including adaptive scenarios, we illustrate the scheme's properties such as convergence and parameter robustness.

• Hornkjøl, Martin; Valnes, Lars Magnus; Ringstad, Geir; Rognes, Marie Elisabeth; Eide, Per Kristian & Mardal, Kent-Andre [Vis alle 7 forfattere av denne artikkelen] (2022). CSF circulation and dispersion yield rapid clearance from intracranial compartments. Frontiers in Bioengineering and Biotechnology. 10, s. 1–14. doi: 10.3389/fbioe.2022.932469. Fulltekst i vitenarkiv Vis sammendrag

  In this paper, we used a computational model to estimate the clearance of a tracer driven by the circulation of cerebrospinal fluid (CSF) produced in the choroid plexus (CP) located within the lateral ventricles. CSF was assumed to exit the subarachnoid space (SAS) via different outflow routes such as the parasagittal dura, cribriform plate, and/or meningeal lymphatics. We also modelled a reverse case where fluid was produced within the spinal canal and absorbed in the choroid plexus in line with observations on certain iNPH patients. No directional interstitial fluid flow was assumed within the brain parenchyma. Tracers were injected into the foramen magnum. The models demonstrate that convection in the subarachnoid space yields rapid clearance from both the SAS and the brain interstitial fluid and can speed up intracranial clearance from years, as would be the case for purely diffusive transport, to days.

• Boon, Wietse; Hornkjøl, Martin; Kuchta, Miroslav; Mardal, Kent-Andre & Ruiz-Baier, Ricardo (2022). Parameter-robust methods for the Biot–Stokes interfacial coupling without Lagrange multipliers. Journal of Computational Physics. ISSN 0021-9991. 467. doi: 10.1016/j.jcp.2022.111464. Fulltekst i vitenarkiv

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• Kuchta, Miroslav; Boon, Wietse; Hornkjøl, Martin; Koch, Timo; Mardal, Kent-Andre & Ruiz-Baier, Ricardo (2022). Parameter-robust Methods for Biot-Stokes and Darcy-Stokes Interfacial Coupling without Lagrange Multipliers. Fulltekst i vitenarkiv
• Kuchta, Miroslav; Boon, Wietse; Holter, Karl; Hornkjøl, Martin; Koch, Timo & Mardal, Kent-Andre [Vis alle 7 forfattere av denne artikkelen] (2022). Fractional operators in coupled multiphysics problems with implicit coupling. Fulltekst i vitenarkiv
• Kuchta, Miroslav; Boon, Wietse; Holter, Karl; Hornkjøl, Martin; Koch, Timo & Mardal, Kent-Andre [Vis alle 7 forfattere av denne artikkelen] (2022). Parameter-robust monolithic solvers for Stokes-Darcy/Biot systems. Fulltekst i vitenarkiv

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