1993 Fiscal Year Final Research Report Summary
Study on Flow Liquid Crystalline Polymers and its Simulation
| Project/Area Number |
04650168
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Fluid engineering
|
|---|
| Research Institution | Osaka University |
|---|
Principal Investigator |
MORI Noriyasu Faculty of Engineering, Osala University associate Prof., 工学部, 助教授 (30124069)
|
|---|
| Project Period (FY) |
1992 – 1993
|
| Keywords | Liquid crystalline polymers / Leslie-Ericksen model / TIF model / Doi model / Squeezing flow / Inlet flow / Numerical calculation / HPC solution |
|---|
| Research Abstract |
In this work the use of some consititutive equations for liquid crystalline fluids is attempted for the simulations in various flow geometries as a first step of the flow analysis in the processing of LCP's. The experimental investigations are also performed using the solutions of hydroxypropylcellulose(HPC).
The Leslie-Ericksen constitutive equation is applied to the clculation of the flows of nematic liquid crystals ; the inlet flows berween parallel plates and the flows through parallel plates containing a projection. The development ofdirector alignment depends on the Ericksen number. The director alignment is also affected by the flow at the large Ericksen numbers, especially in the tilted or vertical alignment. When the spatial change of director alignment becomes steep, the velocity profile changes. In the calculation of the inlet flows using the high viscosity approximation equation the derector aligns parallel to the centerline in the middle part of the parallel plates just below the inlet and this part extends downstream as * approaches the value of one. Furthermore it is found that the optical observation with a polarizing microscope provides useful information about the alignment of LCP's during flows.
The squeezing force cannot ve estimated by only the shear viscosity in the case of anisotropic HPC solutions. The changes of the alignment with time in the squwwsing folws are calculated using the Doi equation. The application of the lubrication approximation to the squeezing flows may enable to analyze the alignment and the flow field of LCP's.
The problems of the polydomain texture and the moleclar tumbling could not include in this work. It is necessary to vestigate them on the use of the Doi equation to the flows of LCP's in future.
|
