horizontal flow field modelling using delft3 d fm

1. Delft, 3rd of November 2015
Frank Platzek (Deltares)
Regina Patzwahl (BAW)
mesoscale horizontal flow-field modelling at a
channel-river junction
Delft Software Days 2015
A behavioral study

2. Delft, 3rd of November 2015
Frank Platzek (Deltares)
Regina Patzwahl (BAW)
more mesoscale horizontal flow-field modelling at a
channel-river junction
Delft Software Days 2015
A behavioral study

3. Delft, 3rd of November 2015
Frank Platzek (Deltares)
Regina Patzwahl (BAW)
Even more mesoscale horizontal flow-field modelling at
a channel-river junction
Delft Software Days 2015
A behavioral study

4. Delft, 3rd of November 2015
Frank Platzek (Deltares)
Regina Patzwahl (BAW)
Even more mesoscale horizontal flow-field modelling at
a (modified) channel-river junction
Delft Software Days 2015
A behavioral study

5. www.baw.de
Outline
1. Geometrical setting
2. Field measurements
3. Scale model
4. Numerical model
5. Lessons learned 2013
6. Lessons learned 2014: Sheet pile wall modelling for beginners
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 7
Introduction
1. Geometrical setting
2. Field measurements
3. Scale model
4. Numerical model
5. Lessons learned 2013
6. Lessons learned 2014: Sheet pile wall modelling for beginners
7. Another channel mouth geometry
8. Results from D-Flow FM
9. Lessons learned
So, what‘s new this
year?

6. www.baw.de
Geometrical setting
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 8
Import of coarse AND fine material
into the channel mouth

7. www.baw.de
04/12/2015
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
Page 9
Geometrical setting
Topography in the vicinity of the channel mouth: groynes, dunes, sediment deposition on upstream
side of the inlet, dregded fairway on the downstream side of the inlet

8. www.baw.de
Depth-averaged ADCP-measurements
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 10
950 m³/s 1700 m³/s
1950 m³/s 840 m³/s
• Flow velocities increase with discharge
• Position of eddy is discharge independent
950 m³/s

9. www.baw.de
ADCP-cross profiles
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 11
Source: Ing. Büro Schmid
• Horizontal eddy (2D-problem)

10. www.baw.de
Scale model
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 12
4 km of river stretch = 67 m of model length
Length Scaling: 1:60
Height Scaling: 1:30
Stationary discharge conditions, non-movable gravel bed
Polystyrol tracer for investigation of transport processes

11. www.baw.de
Numerical model
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 14
• 11 km long river model
• grid types:
• quadrilateral (dx=2m),
river axis aligned,
# of elements: ~ 800.000
• triangular (dx=1,5m),
# of elements: ~ 2.500 000
• discharge at inflow: 986 m³/s
• water level at outflow: 4.71 m
• const. hor. visc.0.0001 m²/s
• 1. and 2. order advection
• Smagorinsky off/ on

12. www.baw.de
Lessons learned 2013
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 15
The modelled flow field in the junction domain is sensitive to:
advection scheme
Constant viscosity
Grid type
„Smagorinsky“
Lower velocities in
the eddy field
Numerical diffusion
„physically correct“?
Arguably improved?
Grid-dependent
results
advection scheme
= crucial choice!
Grid-dependent
results

13. www.baw.de
Lessons learned 2013
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 16
Best modelling result
Quads, Hor. Visc.1.0*10-4
Perot 3, Smag
Field measurements Scale model
• Excellent validation case for modelling mesoscale horizontal recirculation
• Unique combined set of field data, scale model and numerical model data
=> We follow the project with D-FLOW FM for studying purposes

14. www.baw.de
Lessons learned 2014
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 17

15. www.baw.de
Lessons learned 2014
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 18

16. www.baw.de
Lessons learned 2014
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 19
/rough /smooth

17. www.baw.de
Lessons learned 2014
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 20

18. www.baw.de
Lessons learned 2014
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 21

19. www.baw.de
Lessons learned 2014
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 22

20. www.baw.de
Another channel mouth geometry
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 23
1. Widening of cross-section in the main flow -> deposition of bed load and suspended load in the river

21. www.baw.de
Another channel mouth geometry
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 24
1. Widening of cross-section in the main flow -> deposition of bed load and suspended load in the river1. Widening of cross-section in the main flow -> deposition of bed load and suspended load in the river
2. No bed load transport into channel mouth

22. www.baw.de
Another channel mouth geometry
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 25
1. Widening of cross-section in the main flow -> deposition of bed load and suspended load in the river1. Widening of cross-section in the main flow -> deposition of bed load and suspended load in the river
2. No bed load transport into channel mouth
3. No suspended load transport into channel mouth

23. www.baw.de
Another channel mouth geometry
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 26
1. Widening of cross-section in the main flow -> deposition of bed load and suspended load in the river1. Widening of cross-section in the main flow -> deposition of bed load and suspended load in the river
2. No bed load transport into channel mouth
3. No suspended load transport into channel mouth

24. www.baw.de
Another channel mouth geometry
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 28
1. Widening of cross-section in the main flow -> deposition of bed load and suspended load in the river1. Widening of cross-section in the main flow -> deposition of bed load and suspended load in the river
2. No bed load transport into channel mouth
3. No suspended load transport into channel mouth

25. www.baw.de
1. Order advection2. Order advection
Results from numerical model
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 31
No stationarity observable Develops towards a
stable condition

26. www.baw.de
1. Order advection2. Order advection 1. Order advection2. Order advection
Results from numerical model
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 35
No stationarity observable Develops towards a
stable condition
Develops towards a
stable yet different
condition
Develops towards a
stable condition yet
different
+ Smagorinsky

27. www.baw.de
Results
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 38
With the calibration of the current state we identified relevant dependencies of the
results on the model set-up
- the jokers helped to identify the „values“ of the „playing cards“
JOKER
measure
ments

28. www.baw.de
- the modified geometry led to
different dependencies…
Results
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 39
JOKER
measure
ments
…and the values of the playing
cards are unknown

29. www.baw.de
Conclusion
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 40
JOKER?
JOKER
Measure
ments
Very sensitive test case, on the border of model validity:
• point of flow separation
• location and orientation of the eddies
In particular for the modified geometry, where we also lack validation
data from the field.
=> a challenge for a numerical model(ler)

30. Bundesanstalt für Wasserbau
76187 Karlsruhe, Germany
www.baw.de
Thank YOU for your attention
We want to thank for support:
The hydraulic lab (B. Hentschel) at BAW
Colleagues from W2 and W5 at BAW
Colleagues from Deltares

31. www.baw.de
A new channel mouth geometry
Even more horizontal flow field modelling | Frank Platzek, Regina Patzwahl
04/12/2015 Page 42
Analysis of As-is
state
Numerical modelScale model
Numerical model
Telemac3D
Investigation of possible
geometry variations:
Variant X
Fine-tuning of variant X
In respect to transport:
Xplus
Numerical model
Telemac2D
(J. Becker 2014)
Fine tuning of
variant Xplus in
respect to
hydraulic
matters:
Xplusplus
Xplus
Variant X
Xplusplus