Nonequilibrium steady-state response of a nematic liquid crystal under simple shear flow and electric fields

2014 ◽  
Vol 90 (3) ◽  
Author(s):  
Jaka Fajar Fatriansyah ◽  
Yuji Sasaki ◽  
Hiroshi Orihara
Keyword(s):  
Liquid Crystal ◽  
Steady State ◽  
Shear Flow ◽  
Nematic Liquid Crystal ◽  
Electric Fields ◽  
Simple Shear ◽  
Nonequilibrium Steady State ◽  
Simple Shear Flow ◽  
Steady State Response ◽  
State Response

Numerical study of electric field effects on the deformation of two-dimensional liquid drops in simple shear flow at arbitrary Reynolds number

2009 ◽  
Vol 626 ◽  
pp. 367-393 ◽  
Author(s):  
STEFAN MÄHLMANN ◽  
DEMETRIOS T. PAPAGEORGIOU
Keyword(s):  
Steady State ◽  
Shear Flow ◽  
Electric Field ◽  
Electric Fields ◽  
Simple Shear ◽  
Simple Shear Flow ◽  
Physical Parameters ◽  
Shear Stresses ◽  
Two Dimensional ◽  
Liquid Drops

The effect of an electric field on a periodic array of two-dimensional liquid drops suspended in simple shear flow is studied numerically. The shear is produced by moving the parallel walls of the channel containing the fluids at equal speeds but in opposite directions and an electric field is generated by imposing a constant voltage difference across the channel walls. The level set method is adapted to electrohydrodynamics problems that include a background flow in order to compute the effects of permittivity and conductivity differences between the two phases on the dynamics and drop configurations. The electric field introduces additional interfacial stresses at the drop interface and we perform extensive computations to assess the combined effects of electric fields, surface tension and inertia. Our computations for perfect dielectric systems indicate that the electric field increases the drop deformation to generate elongated drops at steady state, and at the same time alters the drop orientation by increasing alignment with the vertical, which is the direction of the underlying electric field. These phenomena are observed for a range of values of Reynolds and capillary numbers. Computations using the leaky dielectric model also indicate that for certain combinations of electric properties the drop can undergo enhanced alignment with the vertical or the horizontal, as compared to perfect dielectric systems. For cases of enhanced elongation and alignment with the vertical, the flow positions the droplets closer to the channel walls where they cause larger wall shear stresses. We also establish that a sufficiently strong electric field can be used to destabilize the flow in the sense that steady-state droplets that can exist in its absence for a set of physical parameters, become increasingly and indefinitely elongated until additional mechanisms can lead to rupture. It is suggested that electric fields can be used to enhance such phenomena.

Effects of chain length and polydispersity on shear banding in simple shear flow of polymeric melts

Soft Matter ◽  
2020 ◽  
Vol 16 (28) ◽  
pp. 6468-6483 ◽  
Author(s):  
Mahdi Boudaghi-Khajehnobar ◽  
Brian J. Edwards ◽  
Bamin Khomami
Keyword(s):  
Steady State ◽  
Shear Rate ◽  
Shear Flow ◽  
Chain Length ◽  
Simple Shear ◽  
Polymer Melts ◽  
Shear Banding ◽  
Simple Shear Flow ◽  
Polydisperse Polymer ◽  
Transient And Steady State

Transient and steady-state shear banding are demonstrated for polydisperse polymer melts as functions of applied shear rate.

scholarly journals Influence of shear flow on the linear response of a nematic liquid crystal to external electric fields

2012 ◽  
Vol 86 (4) ◽  
Author(s):  
Hiroshi Orihara ◽  
Fan Yang ◽  
Yuta Takigami ◽  
Yoshinori Takikawa ◽  
Yang Ho Na
Keyword(s):  
Liquid Crystal ◽  
Shear Flow ◽  
Nematic Liquid Crystal ◽  
Electric Fields ◽  
Linear Response ◽  
External Electric Fields
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