Numerical Simulation of Transient Behaviors of Nematic Liquid Crystalline Flow between Parallel Plates under Magnetic Fields

Abstract

Unsteady behavior of a nematic liquid crystal is simulated by using the Leslie-Ericksen theory as a constitutive equation. After a magnetic field is imposed on nematic flow between parallel plates, the director keeps a symmetric posture with respect to the channel centerline for a certain period, and afterwards, the symmetry is destroyed and the director reorients to the direction parallel to the magnetic field. When the magnetic field intensity is high, the period is short. While pressure gradient at the channel centerline shows the same behavior as that of orientation angle of the director for low magnetic field intensity, it indicates two-stepwise complicated variation before reaching the steady state for high magnetic field intensity. For liquid crystalline flow, pressure depends on the transverse position of a channel. An overshoot phenomenon of pressure near the channel wall is simulated numerically for high magnetic field intensity, which agrees with experimental results.