A hybrid particle-mesh method for incompressible active polar viscous gels
English
Ramaswamy, Rajesh[Max Planck Institute for the Physics of Complex Systems > > > ; MOSAIC Group, Max Planck Institute of Molecular Cell Biology and Genetics, > > > ; Center for Systems Biology]
Bourantas, Georgios[MOSAIC Group, Max Planck Institute of Molecular Cell Biology and Genetics,]
Jülicher, Frank[Max Planck Institute for the Physics of Complex Systems > > > ; Center for Systems Biology]
Sbalzarini, Ivo[Chair of Scientific Computing for Systems Biology > Faculty of Computer Science > > ; MOSAIC Group, Max Planck Institute of Molecular Cell Biology and Genetics > > > ; Center for Systems Biology Dresden,]
[en] We present a hybrid particle-mesh method for numerically solving the hydrodynamic equations of incompressible active polar viscous gels. These equations model the dynamics of polar active agents, embedded in a viscous medium, in which stresses are induced through constant consumption of energy. The numerical method is based on Lagrangian particles and staggered Cartesian finite-difference meshes. We show that the method is second-order and first-order accurate with respect to grid and time-step sizes, respectively. Using the present method, we simulate the hydrodynamics in rectangular geometries, of a passive liquid crystal, of an active polar film and of active gels with topological defects in polarization. We show the emergence of spontaneous flow due to Fréedericksz transition, and transformation in the nature of topological defects by tuning the activity of the system.
