1999 Fiscal Year Final Research Report Summary
Dependence of flow behavior of complex fluids in elongational flows and change in structure on elongational property of fluids
| Project/Area Number |
10450076
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Fluid engineering
|
|---|
| Research Institution | Osaka University |
|---|
Principal Investigator |
NAKAMURA Kiyoji Graduate School of Engineering, Osaka University, Professor, 大学院・工学研究科, 教授 (30029178)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Takehiro Graduate School of Engineering Osaka University, Research Assistant, 大学院・工学研究科, 助手 (40252621)
YASUDA Kazunori Graduate School of Engineering Osaka University, Research Assistant, 大学院・工学研究科, 助手 (80239756)
MORI Noriyasu Graduate School of Engineering, Osaka University, Associate Professor, 大学院・工学研究科, 助教授 (30124069)
|
|---|
| Project Period (FY) |
1998 – 1999
|
| Keywords | elongational flow / complex fluid / viscoelastic fluid / liguid crystalline polymer / rheometer / elongational viscosity |
|---|
| Research Abstract |
We considered flows in which elongational property of complex fluids played an important part. In the present study, we chose polymer solutions (viscoelastic fluid) and liquid crystalline polymers from many complex fluids.
In the study of the flow of polymer solutions, velocity measurement of start-up flow in both a rectangular contraction channel and a rectangular expansion channel was carried out using a laser Doppler velocimeter (LDV). Experiment on flow visualization was also carried out. In addition, viscoelastic star-up flow was numerically investigated. The results indicated that the flow near the contraction and expansion was three-dimensional and the flow behavior of viscoelastic fluids was more complex than that of Newtonian fluids. The results of the numerical simulation showed that the behavior near the contraction and expansion related to the elongational property of polymer solutions.
In study of flow of liquid crystalline polymers, coating flow, one of elongational flows, was investgated. Homogeneous surface alignment of liquid crystals (5CB) was observed for films formed by coating flow with aqueous solutions of hydroxypropylcellulose (HPC). The results of the present study suggested that the flow-induced anisortopic orentation of HPC molecules is responsible for the homogeneous surface alignment of 5CB.
Moreover, a filament-stretching rheometer was made, and growth of the uniaxial elongational viscosity aqueous solution of polyacrylamide was measured.
|
Research Products
(6 results)
