Lagrangian Particle Methods for Biological Systems - Porous Media: Applications in Biological Systems and Biotechnology - page 263

FIGURE 7.2
DPD simulation of the growth deformation and fragmentation of a relatively
soft biofilm. Medium gray represents the substratum, dark gray represents
the flowing fluid, and light gray represents the biofilm. Snapshots are taken
at simulation times of t = 500, 550. . . 900.
FIGURE 7.3
DPD simulation model of the growth and deformation of a medium stiffness
and strength biofilm. Medium gray represents the substratum, dark gray rep-
resents the flowing fluid, and light gray represents the biofilm. Snapshots are
taken at simulation times t = 500, 550. . . 900.
Preliminary results from a DPD model incorporating nutrient substrate
transport, biofilm growth, and hydrodynamic interactions are shown in
Figures 7.2, 7.3, and 7.4 at the same time. The simulation was started with a
seed biofilm DPD particle attached to the bottom surface of a channel, and
gravity drove the fluid flow is from left to right. In the figures, medium gray
represents the substratum, dark gray represents the flowing fluid, and light
gray represents the biofilm. Periodic boundary conditions were applied at the
vertical boundaries: fluid particles exiting the right boundary were reinserted
into the computational domain through the left boundary with a fixed sub-
strate concentration prescribed at the boundary. Three types of biofilm, with
various rigidities, were investigated, namely soft, medium, and rigid biofilms.
For a given geometry and gravitational acceleration, the rigidity of the biofilms