2024-03-29T14:05:07Z
https://niigata-u.repo.nii.ac.jp/oai
oai:niigata-u.repo.nii.ac.jp:00002145
2022-12-15T03:35:02Z
423:424:425
453:454
Electro-Rheological Response of Liquid Crystals under Oscillatory Squeeze Flow
Narumi, Takatsune
See, Howard
Yamaguchi, Yasuhiro
Hasegawa, Tomiichi
日本機械学会
Electro-Rheological Fluid
Liquid Crystal
Squeeze Flow
Oscillatory Flow
Non-Newtonian Fluid
Flow Control
We have investigated the electro-rheological (ER) properties of liquid crystals in an oscillatory squeezing flow. A Micro Fourier Rheometer was utilized to estimate the complex viscosity and phase shift. A clear dip in the phase angle was observed, centred around a frequency which increased with electric field strength. It was found that this critical frequency was proportional to the inverse of the response time required for the liquid crystal molecules to align under the electric field. Similar ER effects to those observed under steady shearing were obtained in the oscillatory flow, but the ER effect at high frequency is smaller than that under no electric field. In other words, a negative ER effect was obtained under low electric fields. A rheological model for the dynamic response was obtained through the control theory and the transfer function thus derived will be useful for estimating the output response in a flow or motion control system.
Japan Society of Mechanical Engineers
2005-08
eng
journal article
VoR
http://hdl.handle.net/10191/6322
https://niigata-u.repo.nii.ac.jp/records/2145
http://doi.org/10.1299/jsmeb.48.524
AA10888815
1340-8054
JSME international journal. Series B-Fluids and thermal engineering
48
3
524
531
https://niigata-u.repo.nii.ac.jp/record/2145/files/14_0021.pdf
application/pdf
1.0 MB
2019-07-29