4 research outputs found
Energy stable and maximum bound principle preserving schemes for the Q-tensor flow of liquid crystals
In this paper, we propose two efficient fully-discrete schemes for Q-tensor
flow of liquid crystals by using the first- and second-order stabilized
exponential scalar auxiliary variable (sESAV) approach in time and the finite
difference method for spatial discretization. The modified discrete energy
dissipation laws are unconditionally satisfied for both two constructed
schemes. A particular feature is that, for two-dimensional (2D) and a kind of
three-dimensional (3D) Q-tensor flows, the unconditional
maximum-bound-principle (MBP) preservation of the constructed first-order
scheme is successfully established, and the proposed second-order scheme
preserves the discrete MBP property with a mild restriction on the time-step
sizes. Furthermore, we rigorously derive the corresponding error estimates for
the fully-discrete second-order schemes by using the built-in stability
results. Finally, various numerical examples validating the theoretical
results, such as the orientation of liquid crystal in 2D and 3D, are presented
for the constructed schemes
Numerical solution of the Ericksen–Leslie dynamic equations for two-dimensional nematic liquid crystal flows
A finite difference method for solving nematic liquid crystal flows under the effect of a magnetic field is developed. The dynamic equations of nematic liquid crystals, given by the Ericksen–Leslie dynamic theory, are employed. These are expressed in terms of primitive variables and solved employing the ideas behind the GENSMAC methodology (Tomé and McKee, 1994; Tomé et al., 2002) [38,41]. These equations are nonlinear partial differential equations consisting of the mass conservation equation and the balance laws of linear and angular momentum. By employing fully developed flow assumptions an analytic solution for steady 2D-channel flow is found. The resulting numerical technique was then, in part, validated by comparing numerical solutions against this analytic solution. Convergence results are presented. To demonstrate the capabilities of the numerical method, the flow of a nematic liquid crystal through various complex geometries are then simulated. Results are obtained for L-shaped channels and planar 4:1 contraction for several values of Reynolds and Ericksen numbers