Approximation of Smectic-A liquid crystals
  In this paper, we present energy-stable numerical schemes for a Smectic-A liquid crystal model. This model involve the hydrodynamic velocity-pressure macroscopic variables $({\bf u},p)$ and the microscopic order parameter of Smectic-A liquid crystals, where its molecules have a uniaxial orientational order and a positional order by layers of normal and unitary vector ${\bf n}$.   We start from the formulation given in \cite{E} by using the so-called layer variable $\phi$ such that ${\bf n}=\nabla \phi$ and the level sets of $\phi$ describe the layer structure of the Smectic-A liquid crystal. Then, a strongly non-linear parabolic system is derived coupling velocity and pressure unknowns of the Navier-Stokes equations $({\bf u},p)$ with a fourth order parabolic equation for $\phi$.   We will give a reformulation as a mixed second order problem which let us to define some new energy-stable numerical schemes, by using second order finite differences in time and $C^0$-finite elements in space. Finally, numerical simulations are presented for $2D$-domains, showing the evolution of the system until it reaches an equilibrium configuration.   Up to our knowledge, there is not any previous numerical analysis for this type of models. 
Francisco Guill\'en-Gonz\'alez and Giordano Tierra
math.NA