where (x, y, z, t) is the vorticity vector and v(x, y, z, t) is the velocity vector. We present an Eulerian, fixed grid, approach to solve the motion of an incompressible fluid, in two and three dimensions, in which In a vortex sheet, is a singular measure concentrated the vorticity is concentrate
A level set-based Eulerian approach for anisotropic wave propagation
โ Scribed by Jianliang Qian; Li-Tien Cheng; Stanley Osher
- Book ID
- 104293933
- Publisher
- Elsevier Science
- Year
- 2003
- Tongue
- English
- Weight
- 294 KB
- Volume
- 37
- Category
- Article
- ISSN
- 0165-2125
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โฆ Synopsis
The geometric optics approximation to high frequency anisotropic wave propagation reduces the anisotropic wave equation to a static Hamilton-Jacobi equation. This equation is known as the anisotropic eikonal equation and has three different coupled wave modes as solutions. We introduce here a level set-based Eulerian approach that captures all three of these wave propagations. In particular, our method is able to accurately reproduce the quasi-transverse, or quasi-S, waves with cusps, which form a class of multi-valued solutions. The level set formulation we use is borrowed from one for moving curves in three spatial dimensions, with the velocity fields for evolution following from the method of characteristics on the anisotropic eikonal equation. We present here our derivation of the algorithm and numerical results to illustrate its accuracy in different cases of anisotropic wave propagations related to seismic imaging.
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