English

A Cartesian-octree adaptive front-tracking solver for immersed biological capsules in large complex domains

Fluid Dynamics 2022-11-30 v1 Computational Physics

Abstract

We present an open-source adaptive front-tracking solver for biological capsules in viscous flows. The membrane elastic and bending forces are solved on a Lagrangian triangulation using a linear Finite Element Method and a paraboloid fitting method. The fluid flow is solved on an octree adaptive grid using the open-source platform Basilisk. The Lagrangian and Eulerian grids communicate using an Immersed Boundary Method by means of Peskin-like regularized Dirac delta functions. We demonstrate the accuracy of our solver with extensive validations: in Stokes conditions against the Boundary Integral Method, and in the presence of inertia against similar (but not adaptive) front-tracking solvers. Excellent qualitative and quantitative agreements are shown. We then demonstrate the robustness of the present solver in a challenging case of extreme membrane deformation, and illustrate its capability to simulate inertial capsule-laden flows in complex STL-defined geometries, opening the door for bioengineering applications featuring large three-dimensional channel structures. The source code and all the test cases presented in this paper are freely available.

Keywords

Cite

@article{arxiv.2211.15814,
  title  = {A Cartesian-octree adaptive front-tracking solver for immersed biological capsules in large complex domains},
  author = {Damien P. Huet and Anthony Wachs},
  journal= {arXiv preprint arXiv:2211.15814},
  year   = {2022}
}

Comments

42 pages, 18 figures

R2 v1 2026-06-28T07:15:53.139Z