| Project/Area Number |
06452068
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
物理学一般
|
|---|
| Research Institution | Tokyo University of Agriculture and Technology |
|---|
Principal Investigator |
TAKAKI Ryuji Tokyo University of Agriculture and Technology, Faculty of Engineering, Professor, 工学部, 教授 (80015065)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KOUDA Akihiro Tokyo University of Agriculture and Technology, Faculty of Engineering, Associat, 工学部, 助教授 (60015039)
SANO Osamu Tokyo University of Agriculture and Technology, Faculty of Engineering, Professo, 工学部, 教授 (80126292)
|
|---|
| Project Period (FY) |
1994 – 1996
|
| Project Status |
Completed (Fiscal Year 1996)
|
| Budget Amount *help |
¥7,400,000 (Direct Cost: ¥7,400,000)
Fiscal Year 1996: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1995: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1994: ¥5,900,000 (Direct Cost: ¥5,900,000)
|
|---|
| Keywords | Fluidized Bed / two-fluid model / linear stability / nonlinear wave / particle cluster / shape parameter / kdV equation / 1 / f spectrum / ソリトン / 圧力差変動 / fゆらぎ |
|---|
| Research Abstract |
Fluctuation of particle distribution in the two-dimensional fluidized bed was investigated both theoretically and experimentally.
In the theory two-fluid model equations are set up and expanded with respect to the amplitude of particle density fluctuation epsilon. In the first order of epsilon a linear stability analysis shows that fluctuations varying in the vertical direction is most unstable. To consider nonlinear effects we assume epsilon=O (k^2), where k is the wave number (weakly nonlinear theory). Then, by the reductive perturbation method a modified kdV equation of a modified kdV-Burgers equation is derived depending on the degree of linear instability. For waves with larger amplitudes the assumption epsilon=O (k) leads to a similar nonlinear equation (Moderately nonlinear theory). This equation is solved to give a large amplitude pulse, a large amplitude periodic wave or a trapezoid wave depending on the volume flux of the fluid. Numerical simulation of the original equations supports these results.
In the experiment many cylindrical particles were arranged in one layr within a thin water channel and random motions of particle clusters were recorded in a video film. By image analyzed of video images, size and shape parameters were measured. At the same time the pressure drop between upstream and downstream sides was measured. Size and shape parameters showed f^<-1> spectra and the pressure drop showed f^<-2> spectrum. A good correlation was confirmed between the pressure drop and the lateral size of the clusters.
|
