1 / 102

Fatih Ecevit Max Planck Institute for Mathematics in the Sciences

High-frequency scattering by a collection of convex bodies. Fatih Ecevit Max Planck Institute for Mathematics in the Sciences. Collaborations. Caltech University of Minnesota Max Planck Institute for MIS Max Planck Institute for MIS University of Minnesota. Akash Anand Yassine Boubendir

van
Télécharger la présentation

Fatih Ecevit Max Planck Institute for Mathematics in the Sciences

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. High-frequency scattering bya collection of convex bodies Fatih Ecevit Max Planck Institute for Mathematics in the Sciences Collaborations Caltech University of Minnesota Max Planck Institute for MIS Max Planck Institute for MIS University of Minnesota Akash Anand Yassine Boubendir Wolfgang Hackbusch Ronald Kriemann Fernando Reitich

  2. I. Electromagnetic & acoustic scattering problems II. High-frequency integral equation methods • Single convex obstacle • Generalization to multiple scattering configurations • Interpretation of the series and rearrangement into periodic orbit sums III. Asymptotic expansions of iterated currents • Asymptotic expansion on arbitrary orbits • Rate of convergence formulas on periodic orbits High-frequency scattering by a collection of convex bodies Outline IV. Numerical examples & acceleration of convergence

  3. I. Electromagnetic & Acoustic Scattering Simulations Governing Equations Maxwell Eqns. Helmholtz Eqn. (TE, TM, Acoustic)

  4. I. Electromagnetic & Acoustic Scattering Simulations Scattering Simulations Basic Challenges: Fields oscillate on the order of wavelength • Computational cost • Memory requirement Numerical Methods: Convergent (error-controllable) • Variational methods (MoM, FEM, FVM,…) • Differential Eqn. methods (FDTD,…) • Integral Eqn. methods(FMM, H-matrices,…) • Asymptotic methods(GO, GTD,…) Demand resolution of wavelength Discretization independent of frequency Non-convergent (error )

  5. I. Combine… Electromagnetic & Acoustic Scattering Simulations Scattering Simulations Basic Challenges: Fields oscillate on the order of wavelength • Computational cost • Memory requirement Numerical Methods: Convergent (error-controllable) • Variational methods (MoM, FEM, FVM,…) • Differential Eqn. methods (FDTD,…) • Integral Eqn. methods(FMM, H-matrices,…) • Asymptotic methods(GO, GTD,…) Demand resolution of wavelength Discretization independent of frequency Non-convergent (error )

  6. II. Radiation Condition: High-frequency Integral Equation Methods Integral Equation Formulations

  7. II. Radiation Condition: Single layer potential: High-frequency Integral Equation Methods Integral Equation Formulations

  8. II. Radiation Condition: Single layer potential: current Single layer density: High-frequency Integral Equation Methods Integral Equation Formulations

  9. II. High-frequency Integral Equation Methods Single Convex Obstacle: Ansatz Single layer density:

  10. II. High-frequency Integral Equation Methods Single Convex Obstacle: Ansatz Single layer density:

  11. II. High-frequency Integral Equation Methods Single Convex Obstacle: Ansatz Single layer density:

  12. II. High-frequency Integral Equation Methods Single Convex Obstacle: Ansatz Single layer density:

  13. II. High-frequency Integral Equation Methods Single Convex Obstacle: Ansatz Single layer density:

  14. II. Highly oscillatory! High-frequency Integral Equation Methods Single Convex Obstacle A Convergent High-frequency Approach Localized Integration:

  15. II. Highly oscillatory! for all n High-frequency Integral Equation Methods Single Convex Obstacle A Convergent High-frequency Approach Localized Integration:

  16. II. Highly oscillatory! for all n Boundary Layers: (Melrose & Taylor, 1985) High-frequency Integral Equation Methods Single Convex Obstacle A Convergent High-frequency Approach Localized Integration:

  17. II. Highly oscillatory! for all n Boundary Layers: (Bruno & Reitich, 2004) (Melrose & Taylor, 1985) High-frequency Integral Equation Methods Single Convex Obstacle A Convergent High-frequency Approach Localized Integration:

  18. II. High-frequency Integral Equation Methods Single Smooth Convex Obstacle • Bruno, Geuzeine, Reitich ………….. 2004 … • Bruno, Geuzeine (3D)…………….. 2006 …

  19. II. holy grail !! High-frequency Integral Equation Methods Single Smooth Convex Obstacle • Bruno, Geuzeine, Reitich ………….. 2004 … • Bruno, Geuzeine (3D)…………….. 2006 …

  20. II. holy grail !! • Domínguez, Graham, Smyshlyaev … 2006 … (circle/sphere) High-frequency Integral Equation Methods Single Smooth Convex Obstacle • Bruno, Geuzeine, Reitich ………….. 2004 … • Bruno, Geuzeine (3D)…………….. 2006 …

  21. II. holy grail !! • Domínguez, Graham, Smyshlyaev … 2006 … (circle/sphere) • Huybrechs, Vandewalle …….…… 2006 … High-frequency Integral Equation Methods Single Smooth Convex Obstacle • Bruno, Geuzeine, Reitich ………….. 2004 … • Bruno, Geuzeine (3D)…………….. 2006 …

  22. II. holy grail !! • Domínguez, Graham, Smyshlyaev … 2006 … (circle/sphere) • Huybrechs, Vandewalle …….…… 2006 … Single Convex Polygon(2D) • Chandler-Wilde, Langdon ………… 2006 … • Langdon, Melenk …………..……… 2006 … High-frequency Integral Equation Methods Single Smooth Convex Obstacle • Bruno, Geuzaine, Reitich ………….. 2004 … • Bruno, Geuzaine (3D)…………….. 2006 …

  23. II. High-frequency Integral Equation Methods Multiple Scattering Configurations

  24. II. High-frequency Integral Equation Methods Multiple Scattering Configurations

  25. II. High-frequency Integral Equation Methods Multiple Scattering Configurations

  26. II. High-frequency Integral Equation Methods Multiple Scattering Configurations

  27. II. High-frequency Integral Equation Methods Multiple Scattering Configurations

  28. II. High-frequency Integral Equation Methods Multiple Scattering Configurations

  29. II. High-frequency Integral Equation Methods Multiple Scattering Configurations

  30. II. High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind:

  31. II. Disjoint Scatterers: High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind:

  32. II. Disjoint Scatterers: Component form: High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind:

  33. II. Disjoint Scatterers: Component form: High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind:

  34. II. Disjoint Scatterers: Component form: High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind:

  35. II. Disjoint Scatterers: Component form: Multiply with the inverse of the diagonal operator High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind: Invert the diagonal:

  36. II. Disjoint Scatterers: Component form: High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind: Invert the diagonal:

  37. II. Disjoint Scatterers: Component form: High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind: Invert the diagonal:

  38. II. Disjoint Scatterers: Component form: High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind: Invert the diagonal:

  39. II. Disjoint Scatterers: … Operator equation of the 2nd kind High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind:

  40. II. Disjoint Scatterers: … Operator equation of the 2nd kind … Neumann series High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind:

  41. II. Disjoint Scatterers: … Operator equation of the 2nd kind … Neumann series is the superposition over all infinite paths of the solutions of the integral equations High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind:

  42. II. Disjoint Scatterers: … Operator equation of the 2nd kind … Neumann series is the superposition over all infinite paths of the solutions of the integral equations twice the normal derivative (evaluated on ) of the field scattered from High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind:

  43. II. Disjoint Scatterers: High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind: Reduction to the Interaction of Two-substructures:

  44. II. Disjoint Scatterers: Generalized Phase Extraction:(for a collection of convex obstacles) High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind: Reduction to the Interaction of Two-substructures:

  45. II. Disjoint Scatterers: Generalized Phase Extraction:(for a collection of convex obstacles) … given by GO High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind: Reduction to the Interaction of Two-substructures:

  46. II. Disjoint Scatterers: Rearrangement into Sums over Periodic Orbits: can be represented as the superposition of the solution of the above integral equations overprimitive periodic orbits High-frequency Integral Equation Methods Multiple Scattering Formulation Integral Equation of the 2nd Kind: Reduction to the Interaction of Two-substructures:

  47. II. High-frequency Integral Equation Methods A Convergent High-frequency Approach

  48. II. High-frequency Integral Equation Methods A Convergent High-frequency Approach

  49. II. High-frequency Integral Equation Methods A Convergent High-frequency Approach

  50. II. High-frequency Integral Equation Methods A Convergent High-frequency Approach

More Related