Hydrodynamic interactions among large populations of swimming micro-organisms.

Blaise Delmotte (1) , Éric Climent (1) , Franck Plouraboué (1)

1 IMFT - Institut de mécanique des fluides de Toulouse

Bio-convection, biofilm forming or mechanics of reproduction are connected to the motility and collective behaviour of micro-organisms. For instance, spermatozoa suspensions exhibit coherent motion whose frequency and lifespan are strongly correlated to semen fertility (Moore et al. 2002). As interplays in many-bodied systems result in intricate patterns, the understanding of these requires an in-depth knowledge of the suspension microstructure and statistics. Representative and reliable statistics require a large number Np of interactive swimmers that many simulation methods can hardly afford [e.g. Np ¼ 40 in Mehandia and Nott (2008) or Np # 216 in Ishikawa et al. (2008)]. In the following, a spherical swimmer model is derived from the classical low Reynolds number framework and implemented in the force-coupling method (FCM) for large populations. Resulting statistics reveals non-trivial spatial arrangements of swimmers depending on their swimming gait.

Mots clés: Micro-swimmers; Low Reynolds number; Active suspensions; Microstructure; Force-coupling method

Domaines: Ingénierie biomédicale; Biomécanique [physics.med-ph]; Mécanique des fluides [physics.class-ph]

Blaise Delmotte, Éric Climent, Franck Plouraboué. Hydrodynamic interactions among large populations of swimming micro-organisms.. Computer Methods in Biomechanics and Biomedical Engineering, 2013, 16 (supp. 1), pp.6-8. ⟨10.1080/10255842.2013.815881⟩. ⟨hal-03526374⟩