A hydrodynamic model for simulating the dynamic temperature in water bodies to calculate the heat budget of lakes and water bodies in spatial and temporatl high resolutions.

1. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Temperature Dynamics Investigation at Small and
Shallow Lakes Using Hydrodynamic Model
Ali Abbasi
Nick van de Giesen
Delft University of Technology
Water Resources Management
August 20, 2014
A. Abbasi & N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

2. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Motivations
Outline
1 Introduction
Motivations
2 Case Study: Lake Binaba
Description
3 Simulation Process
CFD Work
ow
Geometry & Meshing
Solving
4 Results of Simulation
Results
5 Conclusion
Conclusion
A. Abbasi & N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

3. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Motivations
Motivations
Predicting the temperature pro

4. le in reservoirs and lakes?
Inland water bodies are very important parts of the continental land
surface.
Water temperature dynamics can have a profound eect in heat
storage of lakes and water quality.
Heat storage of lakes and reservoirs is essential to estimate
evaporation.
measurements of heat exchange between the atmosphere and water
surface are sparse.
Vertical resolution of available experiments often are not sucient
for assessing small-scale turbulence eects
Water temperature is aected by radiative forcing, air temperature
and wind velocity.
Temperature pro

5. le in reservoirs and lakes related to the both of
water quantity and water quality.
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

6. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Motivations
Why 3-D Model?
Transport processes in water body are inherently three-dimensional:
driven by wind over water surface, surface thermodynamics and
topography of lake.
the non-linearity of some terms in the heat transfer expression at the
air-water interface(no analytic solution)
one-dimensional models are not able to consider horizontal advection
term.
2-D models are not able to capture mechanisms aecting
temperature transport and mixing accurately, specially in
morphometrically complex lakes and reservoirs
Prediction of the
ow

7. eld and temperature dynamics is possible
only through fully 3-D models.
Representation of the boundary geometry in shallow lakes is more
critical that the deep lakes.
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

8. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Motivations
The Aims of Study
To develop a three-dimensional time-dependent hydrodynamic and
heat transfer model(CFD model).
Simulating the eects of wind and atmosphere conditions over a
complex bathymetry.
To predict the circulation patterns as well as the temperature
distribution in the water body.
To compute total heat storage of shallow lakes in order to estimate
evaporation from water surface.
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

9. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Description
Outline
1 Introduction
Motivations
2 Case Study: Lake Binaba
Description
3 Simulation Process
CFD Work
ow
Geometry Meshing
Solving
4 Results of Simulation
Results
5 Conclusion
Conclusion
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

10. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Description
Description
Lake Binaba:
Location: an arti

11. cial lake located in northern Ghana
Surface: the average area of the lake surface is 4.5 km2
Average depth: only 3 m
Maximum depth: 7 m
Usage: a small reservoir, used as a form of infrastructure for the
provision of water
Air temperature:
uctuates between 24 C and 35 C
Water surface temperature: varies from 28 C to 33 C
Climate: (semi-)arid region
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

12. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Description
Location
Lake Binaba:
Figure: Location of lake Binaba
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

13. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Description
Location
Lake Binaba:
Figure: Location of lake Binaba(Google earth)
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

14. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
Outline
1 Introduction
Motivations
2 Case Study: Lake Binaba
Description
3 Simulation Process
CFD Work
ow
Geometry Meshing
Solving
4 Results of Simulation
Results
5 Conclusion
Conclusion
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

15. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
CFD Work
ow
Using powerful, open-source and free of charge tools:
Geometry Meshing Case Setup
Solving
Post
Processing
Point Cloud
QGIS
ArcMap
Salome
Free-CAD
MeshLab
adMesh
BlockMesh
SnappyHexMesh
Salome
Engrid
GMSH
TETGEN
GridGEN
OpenFOAM
ParaFoam
Paraview
Gnuplot
Python
Matplotlib
Up to 60% of User Time
Up to 20%
of User
Time
Up to 20%
of User
Time
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

16. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
Geometry
Preparing geometry of lake includes following steps:
1 Reading the initial point cloud (x,y,z coordinates from text

17. le)
2 Improving the point cloud by interpolating.
3 Generating the STL(STereoLithography)

18. le
4 Cleaning reapairing the STL

19. le
5 Preparing the STL

20. le to input to the mesh generator
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

21. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
Geometry
Reading the initial point cloud (x,y,z coordinates from text

22. le):
It includes only 642 points.
This number of points are not sucient to produce a precise
geometry of lake
(vertical exaggerated by 100)
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

23. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
Geometry
Improving the point cloud by interpolating:
Improved point cloud includes only 68'802 points.
Adding extra points to de

24. ne the water surface boundary in desired
elevation.
Using QGIS( or ArcMap to interpolating points)
(vertical exaggerated by 100)
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

25. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
Geometry
Generating Cleaning the STL(STereoLithography)

26. le:
Using MeshLab to produce the water bottom surfaces.
Using MeshLab adMesh to repair the surfaces.
Using QGIS( or ArcMap to interpolating points)
(vertical exaggerated by 100)
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

27. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
Geometry
Finally, Have a nice surface to generate CFD mesh:
(vertical exaggerated by 100)
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

28. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
Geometry
Flexible for dierent water levels:
Max depth= 4.0 m (vertical exaggerated by 100)
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

29. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
Meshing
Finally, using ' SnappyHexMesh to generate CFD mesh
(vertical exaggerated by 100)
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

30. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
Governing Equations
The
ow

31. eld in a morphometrically complex small lake is solved with the
incompressible RANS(Reynolds Averaged Navier-Stokes) equations:
Continuity Equations
@uj
@xj
= 0;
Momentum Equation
@ui
+
@t
@
@xj
(ujui)
@
@xj
eff
@ui
@xj
+
@uj
@xi
2
3
@uk
@xk
ij
=
@p
@xi
+ gi [1

32. (T Tref )]
Temperature Equation
@T
@t
+
@
@xj
(Tuj) eff
@
@xk
(
@T
@xk
) = ST (z; t)
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

33. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
Turbulence Model
Selecting realizable k turbulence model:
@k
@t
+ uj
@k
@xj
=
@
@xj
+
T
k
@k
@xj
+ T
@ui
@xj
+
@uj
@xi
@ui
@xj
+ GB + Gk+Sk(t; u2)
@
@t
+ uj
@
@xj
=
@
@xj
T
@
@xj
+ C1S C2
2
k +
p
+ C1C3
k
GB + S(t; u2)
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

34. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
Temperature B.C
At the water surface the heat diused away from the lake surface equals
the net surface:
Water Surface
ρ0Cp(αeff
∂ T
∂ z )=Hnet
Hnet=HLA+HLW+HS+HE
HE=hm×ρa(Xs−Xa)×(24×3600×28.4)
hm=0.0016252×U2+0.0007712
HS=hs (Ts−Ta)
hs=2.1954×U2+1.0419
4
HLA=(1−rA) Eair×σTair
Eair=1.24×(1+0.17C2)(
ea
Tair
)
17
HLW=−Ew×σ Tw 4
time, relative humidity,
wind speed, air temperature,
water surface temperature
time,
relative humidity,
wind speed,
air temperature,
water surface
temperature
time,
Relative humidity
air temperature,
Atmosphere condition
time,
water surface
Temperature,
Atmosphere
condition
Incoming shortwave
radiation is included in
the source term
ST (z ,t )=
1
ρ0Cp
η I0 exp(−ηz)
I0=(1−ra) ISinc
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

35. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
Velocity B.C
At the water surface the eects of wind speed should be considered:
Water Surface
Two different
approach
For velocity B.C
ux≠0,
∂ ux
∂ z
=0 ,
u y≠0 ,
∂uy
∂ z
=0, uz=0
Sk=
u3
✴
κ z
Sε=C1ε
ε
k
Sk
u✴=√τ0
ρ0
2 =ρau✴ 2
τ0=ρaCDU10
CD ,10=[κ−1 ln ( 10g
2 )+11.3 ]
CD, 10U10
−2
Implementing the effect
of wind speed in
turbulence equations
(as source terms)
wind shear stress as
Time-dependent shear stress
boundary condition
over the water surface
[νt
∂u
∂ z ]=
τsx
ρ0
[νt
∂u
∂ z
]=
τsx
ρ0
τsx=ρaCD uw √uw 2
+vw 2
τsy=ρaCD vw √uw 2
+vw 2
uz=0
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

36. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
Boundary Condition
Time-dependent parameters over the water surface:
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

37. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
Boundary Condition
Time-dependent parameters over the water surface:
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

38. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
CFD Work
ow
Geometry Meshing
Solving
OpenFOAM
OpenFOAM: Open Source Field Operation and Manipulation
Open-Source Library
Free of Charge
Running in LINUX OS
C++ Library
Linking with PYTHON
New solvers and BCs can be implemented by the user
Running in parallel on distributed processors
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

39. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Results
Outline
1 Introduction
Motivations
2 Case Study: Lake Binaba
Description
3 Simulation Process
CFD Work
ow
Geometry Meshing
Solving
4 Results of Simulation
Results
5 Conclusion
Conclusion
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

40. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Results
Results
Velocity distribution(x) over the water surface(t=10 hr)
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

41. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Results
Results
Vector velocity over the water surface(t=10 hr)
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

42. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Results
Results
Temperature values over the water surface(t=10 hr)
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

43. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Results
Results
Stream lines in the water body(t=10 hr)
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

44. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Results
Results
Temperature distribution on a vertical section(t=10 hr):
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

45. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Results
Results
Temperature distribution on a vertical section(t=32 hr):
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

46. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Results
Results
Comparing the temperature values in probe location:
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

47. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Conclusion
Outline
1 Introduction
Motivations
2 Case Study: Lake Binaba
Description
3 Simulation Process
CFD Work
ow
Geometry Meshing
Solving
4 Results of Simulation
Results
5 Conclusion
Conclusion
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

48. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Conclusion
Conclusion
CFD is a powerful tool in analysing and designing water resources
issues.
Shallow lakes responce fast to atmospheric parameters.
Wind speeds over the water surface can eect signi

49. cantly the
ow
pattern in water body.
Temperature pro

50. les in water body are aected by circulation and
ow

51. eld in water body.
3-D CFD model could be a very powerful tool to simulate
temperature dynamics in shallow lakes.
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

52. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Conclusion
Thanks
Thanks for your attention
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014

53. Introduction
Case Study: Lake Binaba
Simulation Process
Results of Simulation
Conclusion
Conclusion
Questions?
More details: a.abbasi@tudelft.nl
11th International Conference on Hydroinformatics(HIC 2014)
August 2014
New York City, USA
A. Abbasi N.C. van de Giesen TUDelft Temperature Dynamics at Small and Shallow Lakes HIC2014