Downloaded 18 times
Uploaded byDeltares
DSD-INT 2018 Morphodynamic evolution of tidal inlet systems using Delft3D FM: An idealized model study - Nnafie
The document compares the modeling capabilities of Delft3D 4 and Delft3D FM in simulating tidal inlet systems, using a case study in the Wadden Sea. It highlights issues with Delft3D FM, such as excessive diffusion and rapid bed level changes, which lead to inaccuracies at seaward boundaries. The findings suggest further adjustments in grid size and numerical parameters are necessary for improved accuracy in simulations.
More Related Content
Similar to DSD-INT 2018 Morphodynamic evolution of tidal inlet systems using Delft3D FM: An idealized model study - Nnafie
DSD-INT 2018 Morphodynamic evolution of tidal inlet systems using Delft3D FM: An idealized model study - Nnafie
- 1. Delft3D 4 Suitevs. Delft3D FM Suite (D-Morphology) Modeling the evolution of tidal inlet systems Abdel Nnafie Luitze Perk
- 2.
- 3. Test case: Tidalinlets Source: EMODnet, 2014 𝐖𝐚𝐝𝐝𝐞𝐧 𝐒𝐞𝐚 𝐍𝐨𝐫𝐭𝐡 𝐒𝐞𝐚 𝐕𝐥𝐢𝐞𝐥𝐚𝐧𝐝 𝐓𝐞𝐱𝐞𝐥 𝐓𝐞𝐫𝐬𝐜𝐡𝐞𝐥𝐥𝐢𝐧𝐠 𝐀𝐦𝐞𝐥𝐚𝐧𝐝 𝐏𝐢𝐧𝐤𝐠𝐚𝐭 𝐋𝐚𝐮𝐰𝐞𝐫𝐬 𝐒𝐜𝐡𝐢𝐥𝐝 𝐓𝐞𝐫𝐬𝐜𝐡𝐞𝐥𝐥𝐢𝐧𝐠, 𝐳𝐨𝐨𝐦𝐞𝐝 𝐢𝐧 Nether- lands North Sea
- 4. Objective Verification of Delft3DFM relative to Delft3D 4 Test case: Tidal inlet-basin system Models should be able to simulate the ebb-tidal delta+ observed channel-shoal network in tidal basin
- 5. Model description Hydrodynamics: Shallowwater equations ➢ 𝜕𝐷 𝜕𝑡 + 𝛻 ∙ 𝐷 Ԧ𝑣 = 0 ➢ 𝜕𝑣 𝜕𝑡 + 𝛻 ∙ Ԧ𝑣 Ԧ𝑣 + 𝑓𝑒 𝑧 × Ԧ𝑣 = −𝑔𝛻η- 𝑔 𝑢2+𝑣2 𝐶2 𝐷 Ԧ𝑣+ 1 𝐷 (𝛻 ∙ 𝐷υ𝛻) Ԧ𝑣 • Morphodynamics: ➢Van Rijn (1993), bedload + suspended load transport ➢𝐵𝑒𝑑 𝑠𝑙𝑜𝑝𝑒 𝑎𝑐𝑐𝑜𝑢𝑛𝑡𝑒𝑑 𝑓𝑜𝑟. ➢𝐵𝑒𝑑 𝑙𝑒𝑣𝑒𝑙 𝑐ℎ𝑎𝑛𝑔𝑒: Conservation of sediment. ➢Alfa_BN=20; Alpha_BS=5, d50=250 µm. ➢ThetaSD=1 (Factor for erosion of adjacent dry cells), ➢ SedThr=0.2 (Minimum water depth for sediment computations)
- 6. Methodology Run Delft3D 4and Delft3D FM for exactly same configuration with bottom evolution (~76) years Compare bed level evolution simulated by the models FLOW2D3D Version 6.02.13.7545M, Sep 13 2017 (Delft3D_4_03_01) D-Flow FM Version 1.2.0.53941M, Jul 12 2018 (Delft3D_FM_beta_versie_1.4.6) Sensitivity simulations: only M2, ThetaSD=0.1, SedThr=0.1, AlfaBS=1/AlfaBN=1.5 (Default values)
- 7. Model domain 𝒚 𝒙 𝐨𝐩𝐞𝐧 𝐬𝐞𝐚 𝐛𝐚𝐬𝐢𝐧𝐢𝐧𝐥𝐞𝐭 𝑧𝑏 m 𝐒𝐨𝐮𝐭𝐡 𝐖𝐞𝐬𝐭 −𝟏/𝟐𝑳 𝑺,𝒚 𝟎 𝐍𝐨𝐫𝐭𝐡 𝟏 2 3 𝟒 𝑻𝒊𝒅𝒂𝒍 𝑭𝒐𝒓𝒄𝒊𝒏𝒈: 𝐌𝟐 + 𝐌𝟒 + 𝐌𝟔 Northward propagation
- 8.
- 9. Morphodynamics: Delft3D 4vs Delft3D FM animation Delft3D 4 Delft3D FM
- 10. Snapshots t = 0yrDelft3D 4 Delft3D FM
- 11. Snapshots t = 0.44yrDelft3D 4 Delft3D FM
- 12. Snapshots t = 0.88yrDelft3D 4 Delft3D FM
- 13. Snapshots t = 1.32yrDelft3D 4 Delft3D FM
- 14. Snapshots t = 3.07yrDelft3D 4 Delft3D FM
- 15. Snapshots t = 10yrDelft3D 4 Delft3D FM Delft3D FM seems to be too diffusive Problems at seaward boundary
- 16. Evolution height bedlevel With Delft3D FM, bed level changes are more rapid than with Delft3D 4 (order months)
- 17.
- 18. Snapshots t = 0yr Delft3D FM, A_BS=5,A_BN=20Delft3D FM, A_BS=1,A_BN=1.5
- 19. Snapshots t = 0.44yr Delft3D FM, A_BS=5,A_BN=20Delft3D FM, A_BS=1,A_BN=1.5
- 20. Snapshots t = 0.88yr Delft3D FM, A_BS=5,A_BN=20Delft3D FM, A_BS=1,A_BN=1.5
- 21. Snapshots t = 1.32yr Delft3D FM, A_BS=5,A_BN=20Delft3D FM, A_BS=1,A_BN=1.5
- 22. Snapshots t = 3.07yr Delft3D FM, A_BS=5,A_BN=20Delft3D FM, A_BS=1,A_BN=1.5
- 23. Snapshots t = 10yr Delft3D FM, A_BS=5,A_BN=20Delft3D FM, A_BS=1,A_BN=1.5
- 24.
- 25. How about thehydrodynamics? ➢Both models are run for a couple of tidal cycles ➢Comparison water elevation, velocity and discharge
- 26.
- 27.
- 28.
- 29. Discharge trough tidalinlet Hydrodynamics in the area of the tidal inlet seem to be approximately the same Large differences in velocity at the seaward boundaries
- 30. Conclusions ➢Delft3D FM seemsto be too diffusive, bed level changes appear rather quickly. ➢Problems at the boundaries. ➢Is Delft3D FM ready for application? ➢Outlook: different grid size, numerical parameters, etc…. ➢Other suggestions from the audience?
- 31. Thank you Source: EMODnet,2014 𝐖𝐚𝐝𝐝𝐞𝐧 𝐒𝐞𝐚 𝐍𝐨𝐫𝐭𝐡 𝐒𝐞𝐚 𝐕𝐥𝐢𝐞𝐥𝐚𝐧𝐝 𝐓𝐞𝐱𝐞𝐥 𝐓𝐞𝐫𝐬𝐜𝐡𝐞𝐥𝐥𝐢𝐧𝐠 𝐀𝐦𝐞𝐥𝐚𝐧𝐝 𝐏𝐢𝐧𝐤𝐠𝐚𝐭 𝐋𝐚𝐮𝐰𝐞𝐫𝐬 𝐒𝐜𝐡𝐢𝐥𝐝 𝐓𝐞𝐫𝐬𝐜𝐡𝐞𝐥𝐥𝐢𝐧𝐠, 𝐳𝐨𝐨𝐦𝐞𝐝 𝐢𝐧 Nether- lands North Sea