| dc.description.abstract | Porous scaffold materials have been widely used in biological tissue
engineering. It is known that fluid flow in porous media significantly
increases the supply of oxygen and other nutrients to cells seeded in the
porous material, and speeds up the clearance of metabolic end products. Local
shear stress distribution is a function of media flow rate, viscosity and the
porous scaffold micro-structure. This research project aims to investigate fluid
movement in porous structures by using a lattice Boltzmann method. This new
numerical method models the fluid as a collection of identical particles with
collision and propagation procedures, and has been shown as an alternative
and efficient numerical solver of Navier-Stokes equations, in particular for
flows in complex geometries. The numerical scheme is verified using flow in
a two-dimensional channel, as well as in three-dimensional ducts with
constant shapes, where analytical solutions are available. 2D porous structures
originated from micro-CT images are then used to study the flow and wall
shear stress distribution. One of the advantages of the lattice Boltzmann
method is that the shear stress can be computed directly from the local
distribution function and has the same accuracy with the velocity profile.
Fluid patterns and wall shear stress distribution in 3D porous structures, which
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are reconstructed from the micro-tomographic slices, have been investigated
under different flow rates, viscosity and geometrical structures. Results from
this project demonstrate that lattice Boltzmann method is suitable for flow
modelling in scaffold materials. It provides detailed information on localized
velocity and stress distributions, which can be used to improve the design of
the scaffold for cell and tissue engineering. | en_US |
