Effect of electric field and temperature gradient on the orientational dynamics of liquid crystals in a microvolume cylindrical cavity.
We have considered a homogeneously aligned liquid crystal (HALC) microvolume confined between two infinitely long horizontal coaxial cylinders and investigated dynamic field pumping, i.e., studied the interactions between director, velocity, and electric E fields as well as a radially applied temperature gradient inverted Delta T, where the inner cylinder is kept at a lower temperature than the outer one. In order to elucidate the role of inverted Delta T in producing hydrodynamic flow u, we have carried out a numerical study of a system of hydrodynamic equations including director reorientation, fluid flow, and temperature redistribution across the HALC cavity. Calculations show that only under the influence of inverted Delta T does the initially quiescent HALC sample settle down to a stationary flow regime with horizontal component of velocity u(eq)(r). The effects of inverted Delta T and of the size of the HALC cavity on magnitude and direction of u(eq)(r) have been investigated for a number of hydrodynamic regimes. Calculations also showed that E influences only the director redistribution across the HALC but not the magnitude of the velocity u(eq)(r).
Zakharov
A V
AV
Saint Petersburg Institute for Machine Sciences, Russian Academy of Sciences, Saint Petersburg 199178, Russia. avz02@yahoo.com
Vakulenko
A A
AA
Romano
Silvano
S
D004553:Electric Conductivity; D004560:Electricity; D050866:Liquid Crystals / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors