1. WP3 : Flood Propagation Computation On The ‘Isolated Building Test Case’ And The ‘Model City Flooding Experiment ’ B. Noël, Soares S., Y. Zech Université catholique de Louvain

2. IMPACT - 3rd Workshop Novembre 20032 Overview Numerical Model The ‘Isolated Building Benchmark’ –Numerical modelling –Numerical results –Sensitivity analysis The ‘Model City Benchmark’ –Numerical modelling –Numerical results –Sensitivity analysis

3. IMPACT - 3rd Workshop Novembre 20033 Overview Numerical Model The ‘Isolated Building Benchmark’ –Numerical modelling –Numerical results –Sensitivity analysis The ‘Model City Benchmark’ –Numerical modelling –Numerical results –Sensitivity analysis

4. IMPACT - 3rd Workshop Novembre 20034 Numerical Model 2D finite-volume method First-order scheme Flux evaluated by Roe’s scheme Non-Cartesian grids allowed ‘Soares Frazão S., 2002 PHD Thesis ’

5. IMPACT - 3rd Workshop Novembre 20035 Overview Numerical Model The ‘Isolated Building Benchmark’ –Numerical modelling –Numerical results –Sensitivity analysis The ‘Model City Benchmark’ –Numerical modelling –Numerical results –Sensitivity analysis

6. IMPACT - 3rd Workshop Novembre 20036 The ‘Isolated Building Benchmark’ Numerical modelling (2-mesh grid) – Grid : Square meshes Quadrangular meshes

7. IMPACT - 3rd Workshop Novembre 20037 The ‘Isolated Building Benchmark’ Numerical modelling – Building neighbouring

8. IMPACT - 3rd Workshop Novembre 20038 The ‘Isolated Building Benchmark’ Numerical modelling – Grid mean size : 5 x 5 cm – CFL number : 0.9 –Time duration : ± 2 h – CPU : AMD XP1800+ (128Mb)

9. IMPACT - 3rd Workshop Novembre 20039 The ‘Isolated Building Benchmark’ Numerical results

10. IMPACT - 3rd Workshop Novembre 200310 The ‘Isolated Building Benchmark’ Numerical results – Water level :

11. IMPACT - 3rd Workshop Novembre 200311 The ‘Isolated Building Benchmark’ Numerical results – Water level (t = 10 s) :

12. IMPACT - 3rd Workshop Novembre 200312 The ‘Isolated Building Benchmark’ Numerical results – Velocity field (t = 5 s) : NumericalExperimental Noël, Spinewine 2003 - UCL

13. IMPACT - 3rd Workshop Novembre 200313 The ‘Isolated Building Benchmark’ Numerical results – Velocity Intensity (t = 5 s) : NumericalExperimental Noël, Spinewine 2003 - UCL

14. IMPACT - 3rd Workshop Novembre 200314 The ‘Isolated Building Benchmark’ Sensitivity analysis – Manning roughness coefficient

15. IMPACT - 3rd Workshop Novembre 200315 The ‘Isolated Building Benchmark’ Sensitivity analysis – Initial downstream water-depth

16. IMPACT - 3rd Workshop Novembre 200316 Overview Numerical Model The ‘Isolated Building Benchmark’ –Numerical modelling –Numerical results –Sensitivity analysis The ‘Model City Benchmark’ –Numerical modelling –Numerical results –Sensitivity analysis

17. IMPACT - 3rd Workshop Novembre 200317 The ‘Model City Benchmark’ Numerical modelling (channelled) Mesh XXX

18. IMPACT - 3rd Workshop Novembre 200318 The ‘Model City Benchmark’ Numerical modelling (10-mesh grid) Mesh XXX

19. IMPACT - 3rd Workshop Novembre 200319 The ‘Model City Benchmark’ Numerical modelling (original) Mesh XXX

20. IMPACT - 3rd Workshop Novembre 200320 The ‘Model City Benchmark’ Numerical modelling (10-mesh grid)

21. IMPACT - 3rd Workshop Novembre 200321 The ‘Model City Benchmark’ Numerical modelling – Topography reconstruction

22. IMPACT - 3rd Workshop Novembre 200322 The ‘Model City Benchmark’ Numerical modelling – Upstream reservoir Dimensions : unknown but seen on picture  about 1 meter of longitudinal length  lateral bed level similar to the bed level of upstream end of channel Best way to model : decrease bed level of feeding tank and fill it with water at rest  numerical crash at corner of reservoir

23. IMPACT - 3rd Workshop Novembre 200323 The ‘Model City Benchmark’ Numerical modelling – Upstream reservoir bed level of the upstream end of channel Inlet introduced at the upstream end of the prolonged channel Inlet Walls

24. IMPACT - 3rd Workshop Novembre 200324 The ‘Model City Benchmark’ Numerical modelling – Grid mean size : 2.5 x 2.5 cm – CFL number : 0.1 – Time duration : ± 5h. – Computer : AMD XP1800+ (128Mb)

25. IMPACT - 3rd Workshop Novembre 200325 The ‘Model City Benchmark’ Numerical results – Test cases 1a & 1b (t = 20 s) : Staggered layer : - velocity decreased - water level increased in the building layer

26. IMPACT - 3rd Workshop Novembre 200326 The ‘Model City Benchmark’ Numerical results – Test cases 2a & 2b (t = 20 s) : Staggered layer : - velocity decreased - water level increased in the building layer

27. IMPACT - 3rd Workshop Novembre 200327 The ‘Model City Benchmark’ Numerical results – Test cases 3a & 3b (t = 20 s) : Low inflow : 60 l/s High inflow : 100 l/s

28. IMPACT - 3rd Workshop Novembre 200328 The ‘Model City Benchmark’ Numerical results – Test cases 4a & 4b (t = 20 s) : Buildings as bed elevation (15 cm):

29. IMPACT - 3rd Workshop Novembre 200329 The ‘Model City Benchmark’ Numerical results – Test cases 4a & 4c (t = 20 s) : High friction (n = 10 s/m 1/3 ): - water lost in buildings - maximum water level moves downstream and is a few decreased

30. IMPACT - 3rd Workshop Novembre 200330 The ‘Model City Benchmark’ Sensitivity analysis – Downstream boundary condition

31. WP3 : Flood Propagation Computation On The ‘Isolated Building Test Case’ And The ‘Model City Flooding Experiment ’ B. Noël, Soares S., Y. Zech Université catholique de Louvain