1 / 30

Point-implicit diffusion operator in a moving particle method ( MPPM )

Point-implicit diffusion operator in a moving particle method ( MPPM ). Yao-Hsin Hwang Department of Marine Engineering National Kaohsiung Marine University. Diffusion operator. Time-step constraint for explicit scheme Implicit scheme: Iteration Numerically stable without iteration.

odina
Download Presentation

Point-implicit diffusion operator in a moving particle method ( MPPM )

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. Point-implicit diffusion operator in a moving particle method (MPPM) Yao-Hsin Hwang Department of Marine Engineering National Kaohsiung Marine University

  2. Diffusion operator • Time-step constraint for explicit scheme • Implicit scheme: Iteration • Numerically stable without iteration

  3. Features of existing particle methods • SPH, MPS, FVPM…. • Material particles (mass point, global mass conservation) • Operators realized with randomly particle cloud

  4. Disadvantages of existing schemes • Inaccurate (inconsistent) operator realization (particle smoothing) —continuity constraint • Assignment of boundary condition • Particle management (impractically clustered or dispersive) • Computationally inefficient

  5. Essentials of MPPM (1) • Inserted pressure mesh to realize pressure-related operators • Background mesh and length scale • Local mass conservation • Particle as observation point

  6. Essentials of MPPM (2) • No particle management constraint • Feasible non-uniform distribution • No special boundary treatment • Constant and diagonally dominant coefficient matrix of pressure equation

  7. Diffusion Procedure • Equation • Laplacian ,

  8. Explicit Operator • Scheme • Time-step constraint

  9. Implicit Operator • Scheme • Iteration required

  10. Point-implicit Operator • Operator

  11. Point-implicit Operator • Scheme A • Scheme B

  12. Effective-Time Step • Scheme A • Scheme B

  13. Stability Limits • Scheme A • Scheme B

  14. Three-Point Analysis(1) • Boundary conditions: • Solution at • Results

  15. Three-Point Analysis(2) Results

  16. Pure Diffusion(1) • Particle distribution

  17. Pure Diffusion(2)

  18. Pure Diffusion(3)

  19. Cavity Flow(1)

  20. Cavity Flow Re=10

  21. Cavity Flow(2)

  22. Cavity Flow(3)

  23. Cavity Flow(4)

  24. Cavity Flow(5)

  25. Backward-Facing Step Flow(1)

  26. Backward-Facing Step Flow(2)

  27. Backward-Facing Step Flow(3)

  28. Backward-Facing Step Flow(4)

  29. Backward-Facing Step Flow(5)

  30. Backward-Facing Step Flow(6)

More Related