2005 Fiscal Year Final Research Report Summary
On an analysis globally in time of solutions for surface waves
| Project/Area Number |
15540200
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Global analysis
|
|---|
| Research Institution | Tokyo Institute of Technology |
|---|
Principal Investigator |
IGUCHI Tatsuo Tokyo Inst.of Tech., Graduate School of Science and Engineering, Associate Professor, 大学院・理工学研究科, 助教授 (20294879)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MIYAKAWA Tetsuro Kanazawa Univ., Graduate School of Natural Science and Technology, Professor, 大学院・自然科学研究科, 教授 (10033929)
NISHIBATA Shinya Tokyo Inst.of Tech., Graduate School of Information Scinece and Engineering, Associate Professor, 大学院・情報理工学研究科, 助教授 (80279299)
KAGEI Yoshiyuki Kyushu Univ., Faculty of Mathematics, Associate Professor, 大学院・数理学研究院, 助教授 (80243913)
|
|---|
| Project Period (FY) |
2003 – 2005
|
| Keywords | surface wave / KdV equation / Kawahara equation / forced KdV equation / Navier-Stokes equations / hyperbolic-parabolic system / long wave approximation / group symmetry |
|---|
| Research Abstract |
The KdV equation and the Kawahara equation were derived formally from the basic equations for surface waves as long wave approximations. After rewriting the equations in an appropriate non-dimensional form, we have two non-dimensional parameters δ and ε the ratio of the water depth to the wave length and the ratio of the amplitude of the free surface to the water depth, respectively. The limit δ→0 corresponds to the long wave approximation. More precisely, the limit δ=ε^2→0 corresponds to the KdV limit and the limit δ=ε^4→0 corresponds to the Kawahara limit. T.Iguchi gave mathematically rigorous justifications for the KdV and the Kawahara limits and proved that the solutions of these approximate equations in fact approximate the solutions of the original basic equations for an appropriate long time interval. He also analyzed an effect of the presence of an uneven bottom to these long wave approximations.
T.Miyakawa investigated the Navier-Stokes equations for a two-dimensional incompres
… More
sible viscous fluid in the cases where the fluid is occupied the entire space or outside of the unit disc. He discovered the relation between the group symmetries of the solution and the space-time decay properties of the solution. He also investigated the Euler equation for a two-dimensional incompressible ideal fluid occupied an exterior domain and discovered a relation between the square integrability of the pressure and the effect of the flow to the obstacle.
S.Nishibata investigated the asymptotic behavior in time of the spherically symmetric solution for compressible Navier-Stokes equations in the exterior domain of the sphere. He proved that a stationary solution is asymptotically stable under suitable assumptions for the initial data and the external forces. He did not suppose any smallness conditions for the data.
Y.Kagei investigated the asymptotic stability of a stationary solution for the compressible Navier-Stokes equations in the half-space. He discovered a nice solution formula to the linearized problem. By using the formula and carrying out the analysis very carefully for the oscillatory integrals, he obtained the best possible decay estimates and proved the asymptotic stability. Less
|
