|
Development of 1D fluid Models using the Cosserat Theory
Numerical Simulation and Applications to Haemodynamics
Prof. Fernando Carapau
Departamento de Matematica
Universidade de Evora
Portugal
flc@uevora.pt
Abstract: The aim of this talk is the development and
study of 1D models using the Cosserat director theory. In particular we
study mathematical models for blood flow in the vascular system. We consider
blood modeled both as an incompressible viscous and viscoelastic fluid.
Starting with the exact three-dimensional equations for an incompressible
viscous or viscoelastic fluid, a system of one-dimensional nonlinear
equations is derived for axisymmetric motion inside a slender surface of
revolution with circular cross section. This system is obtained by
introducing an approximate velocity field into weighted integrals of the
momentum equation over the circular cross section. This approximate velocity
is obtained by using the Cosserat theory in fluid dynamics.
In this talk we apply the Cosserat theory to both Newtonian and
non-Newtonian fluids in tubes. For a specific model and geometry we obtain
the unsteady relationship between average pressure gradient and volume flow
rate over a finite section of the tube and the corresponding equation for
the wall shear stress. Attention is focused on the steady case with rigid
and impermeable walls with and without swirling motion, and flow properties
as existence, uniqueness and stability of steady solutions are also given. |