BrIHne‐Jet‐Spreading: A new
model to simulate the near
field region of brine jet
discharges
International Conference on Desalination, Environment And Marine
Outfall Systems
13-16 April 2014
Pilar Palomar
(palomarmp@unican.es)
In the Mediterranean Sea…
Posidonia oceanica
Endemic ecosytem
Extremely high ecological value.
Protected by the European Legislation
(Directiva 92/43/CEE)
In the Mediterranean Sea,
Atlantic Ocean…
Cymodocea nodosa
Posidonia ocanica
4
5
Mollusks
Coral reefs
Scientific
evidence of
impacts of brine
on some marine
ecosystems
Equinoderms
Fish (larvae, juveniles)
Seagrasses
Brine discharge
systems
Overflow spillway in a cliff
discharge
Discharge on a slab beach
▪Higher dilutions than other
systems
▪ The most used in current
desalination plants
discharge on a channel
flowing to seawaters
Single port jet outfall discharge
Multiport jets outfall discharge
Dilution required to
fulfill environmental
conditions
Average salinity in Mediterranean Sea; CA ≈ 37.5 psu
Conversion rate (RO); R = 45 %
Brine saline concentration; Co ≈ 68 psu
Critical salinity limit established to protect the Posidonia
oceanica seagrass: Clim = 38.5 psu
It is required a Dilution rate ≈ 30 in the
area of segrasses to protect
Very high dilutions are needed to
accomplish with water quality
standards.
Discharges through jets are required
Brine jet discharge
behavior
Brine has negative
buoyancy in the sea
Spreading layer
Hypersaline plume
FAR FIELD REGION
Jet
(intermediate field)
NEAR FIELD REGION
Spreading
layer
Jet
Brine jet discharge
behavior near field
region
Numerical
modeling
FOR AN ENVIRONMENTAL DESIGN OF BRINE DISCHARGES, NUMERICAL MODELING
IS AN ESSENTIAL PREDICTION TOOL TO ASSESS THE PERFORMANCE OF THE
WATER QUALITY STANDARDS ESTABLISHED ON THE RECEIVING WATER BODY
Receiving water
quality criteria
Marine climate
conditions
.
∂u ∂v ∂w
=0
+ +
∂x ∂y ∂z
∂u i
∂u i
1 ∂p
µ ∂ 2ui
+ Fvi +
=−
+uj
ρ ∂x j
ρ ∂x j ∂x j
∂t
∂x j
Brine properties and
discharge conditions
Numerical
modeling
Commercial models: CORMIX, CORJET,
UM3 (Visual Plumes), JetLag (VISJET)
Dimensional
analysis
NUMERICAL
APPROACHES
FOR BRINE
DISCHARGES
Simple
models
Integration of
differential
equations
CFDs,
(Hydrodynamics..)
Advanced
complex
models
(in development
Time consumig)
Commercial model
limitations
CORJET, UM3 and JetLag
Integral models
As they assume unlimited environment, they can only simulate the JET PATH
As these models can only simulate the jet behavior, environmental authorities
sometimes impose environmental conditions (such as, critical salinity limits) at
the impact with bottom point.
This is a rather conservative approach since dilution achived along the spreading
layer is significant
Commercial model
Validation
Validated with data published
by various authors (not with
other num. Models)
Zt: TERMINAL RISE HEIGHT
2.7
2.5
2.3
Commercial models
underestimate jet
path dimensions
2.1
Zt/LM
1.9
1.7
1.5
1.3
1.1
0.9
0.7
25
30
35
40
45
50
55
60
65
Initial discharge angle, θ
CORJET
UM3
JETLAG
Cipollina
Kikkert_LA
Roberts
Shao
Papakonstantis
Roberts, P. J. W., Ferrier, A., Daviero, G. (1997). “Mixing in inclined dense jets”. Journal of Hydraulic Engineering, vol. 123, No 8, pp. 693 - 699.
Shao, D., Law, A. W. K. (2010, a). “Mixing and boundary interactions of 30º and 45º inclined dense jets”. Environmental Fluid Mechanics, vol. 10, nº 5,
Papakonstantis, I. G., Christodoulou, G. C., Papanicolau, P. N. (2011, b). “Inclined negatively buoyant jets 1: Geometrical characteristics”. Journal of
Hydraulic Research, vol. 49, No. 1, pp. 13 - 22.
Kikkert, G. A., Davidson, M. J., Nokes, R. I. (2007). “Inclined negatively buoyant discharges”. Journal of Hydraulic Engineering, vol. 133, pp. 545 – 554.
Cipollina, A., Brucato, A., Grisafi, F., Nicosia, S.(2005). “Bench-Scale investigation of inclined dense jets”. Journal of Hydraulic Engineering, vol. 131, no 11,
Commercial model
Validation
Si: CENTERLINE DILUTION AT THE RETURN
IMPACT POINT
2.0
…and overall
underestimate
dilution rates
1.8
1.5
Si/ Frd
1.3
1.0
0.8
0.5
0.3
0.0
25
30
35
40
45
50
55
60
65
Initial discharge angle, θ
CORJET
UM3
JETLAG
Kikkert_LA
Roberts
Shao
Papakonstantis
Commercial model
Validation
Accuracy degree of commercial models for brine jets discharged into
stagnant and dynamic ambients
It must be
considered in
brine discharge
designs, couplig
model studies,
etc.!!
Analysis and validation of
commercial models for brine
discharges
FACED WITH THE UNCERTAINTY IN
THE USE OF COMMERCIAL
MODELS
UNKNOWLEDGE REGARDING THE
HYDRODYNAMIC AND MIXING
PROCESS INVOLVED IN BRINE
DISCHARGES
EXPERIMENAL STUDY
OF BRINE JET
DISCHARGES
(to better understand the
flow, to generate a data base
for calibration and
validation)
Experimental study of
brine discharges
IH CANTABRIA LABORATORY
Experimental study of
brine discharges
IH CANTABRIA LABORATORY
Experimental study of
brine discharges
ADVANCED LASER OPTICAL TECHNIQUES (PIV and PLIF) HAVE BEEN APPLIED TO
EXPERIMENTALLY STUDY BRINE JET DISCHARGES
Laser
Brine flow discharged into the test tank
Instantaneous velocity
flow fields
Instantaneous concentration
flow fields
PIV and PLIF cameras
Images storage, data postprocessing
Data post-processing
Experimental study of
brine discharges
Various:
Densimetric Froude Number (15<Frd<40)
Initial discharge angle (15º<θ<75º)
Bottom slope (0<m<4%)
Experimental study of
brine discharges
JET FLOW FIELDS:
Velocity modulus
Snapshots concentration image
Averaged dilution
Turbulent concentration
Vertical and horizontal velocity components
Vorticity
Experimental study of
brine discharges
BRINE JET TRANSVERSE PROFILES
Hypotheses assumed:
▪ Self-similarity?
▪ Gaussian profile?
Velocity profiles
Concentration profiles
Experimental study of
brine discharges
SPREADING LAYER FLOW FIELDS
Average dilution
Horizontal and vertical average velocity
Horizontal and vertical turbulent velocity
Experimental study of
brine discharges
SPREADING LAYER TRANSVERSE
PROFILES
Concentration profiles
Velocity profiles
FACED WITH THE
COMMERCIAL MODEL
LIMITATIONS
CONSIDERING THE KNOWLEDGE
AND THE EXPERIMENTAL
GENERATED
DEVELOPING OF NEW
TOOLS (“BRIHNE”) TO
SIMULATE BRINE
DISCHARGES
(intermediate step)
New “BRIHNE” tools
Numerical approaches obtained from
scientific publications.
DEVELOPED BY THE IH
CANTABRIA, supported by the
Ministry of Environment in
Spain
“BRIHNE”
TOOLS
Programmed in MATLAB
Calibrated with PIV-PLIF experimental data
ONLINE RUN:
www.brihne.ihcantabria.com
New “BRIHNE” tools
Turbulent jet
(near field region)
Hypersaline Plume
(Far field region)
Spreading layer
(transition flow)
BrIHne-Jet
BrIHne-Plume2D
BrIHne-Plume3D
BrIHne-Jet-Plume
BrIHne-Jet-Spreading
BrIHne-MJets
“BRIHNE” tools
input data
interface
Load input
data
Recommended input data values
Technical specifications document
Warning” file
Save input
data
Run the model
(instantaneous run)
www.brihne.ihcantabria.co
“BRIHNE” tools
results
interface
Excel file with the
numerical values of
the evolution of the
flow behavior
“Pdf” results report
BRIHNE-JET-SPREADING
Simulation of the near field
region of a brine jet discharge
Jet path
BrIHne-Jet-Spreading
modeling scheme
Spreading layer
Input data:
Brine effluent properties // Marine environment conditions // discharge design parameters
BrIHne-Jet-Spreading
numerical approach
DIMENSIONAL ANALYSIS FORMULAS (buoyant jets)
For an specific discharge angle (θ), the brine flow characteristics (trajectory, dilution) mainly
depends on the port diameter (do) and the Densimetric Froude Number (Fo).
Calibration of dimensional analysis formulas to
characterize the full near field region
BrIHne-Jet-Spreading
calibration
Full near field region (from the nozzle to the end of the spreading layer)
Kij : dimensional analysis
coefficients
experimentaly
obtained for each variable at
each point of the flow trajectory
and for all discharge angles
considered
BrIHne-Jet-Spreading
capabilities
Capabilities
Simulation of the whole near field region of a brine jet discharge, jet and
spreading layer up to the begining of the far field region
Applicable to jets with various discharge angles in the range of realistic
designs: 15º, 30º, 45º, 60º and 75º.
It considers the particular features of inclined negatively buoyant jets
relative to classical neutral jets (non-symmetric transverse profiles).
BrIHne-Jet-Spreading
capabilities
Capabilities
As results, it provides the spreading layer velocity and concentration
profiles (thickness and shape), which can be used as “coupling” conditions
for a far field region hydrodynamic model
A good agreement with experimental data ensures feasibility of Brihne-JetSpreading in the simulation of actual desalination plant discharges
Limitations
Stagnant environment, steady model
Bi-dimensional (Three-dimensional case in development)
Example of graphical results
of BrIHne-Jet-Spreading
Validation of
BrIHne-Jet-Spreading
Numerical results of BrIHne-Jet-Spreading have been compared with
experimental data published by various authors, for variables at singular points
of the flow.
JET PATH
Upper edge, terminal rise height (Zt); centerline dilution at the return point (Sr)
Sr: CENTERLINE DILUTION AT THE RETURN POINT
Zt: TERMINAL RISE HEIGHT
2.3
3.2
2.0
2.8
1.8
2.4
1.5
Sr/ Fo
Zt /LM
2.0
1.6
1.2
1.3
1.0
0.8
0.5
0.8
0.3
0.4
0.0
0.0
10
10
20
30
40
50
60
70
20
30
Kikkert_LIF
Roberts
Shao
Papakonstantis
50
60
70
80
Initial discharge angle, θo
Initial discharge angle, θ
Cipollina
40
80
Present study
Kikkert_LIF
Roberts
Shao
Papakonstantis
BrIHne-Jet-Spreading
Validation of
BrIHne-Jet-Spreading
SPREADING LAYER
Layer thickness (Zs) and centerline dilution at the end of the spreading layer (Ss)
Ss: SPREADING LAYER CENTERLINE DILUCIÓN AT THE
END OF THE NEAR FIELD REGION
Zs: SPREADING LAYER THICKNESS AT THE END OF
THE NEAR FIELD REGION
3.0
1.5
2.8
2.5
1.3
2.3
2.0
Ss /Fo
Zs/ doFo
1.0
0.8
1.8
1.5
1.3
1.0
0.5
0.8
0.5
0.3
0.3
0.0
0.0
10
20
30
40
50
60
70
80
10
20
30
40
Initial discharge angle, θo
Roberts
BrIHne-Jet-Spreading
50
60
70
80
Initial discharge angle, θo
Roberts
BrIHne-Jet-Spreading
Conclusions
▪ “brIHne” tools are models focused on brine discharges, calibrated with PIV
and LIF experimental data to achieve more feasible numerical simulations in
actual desalination plants projects
▪ BrIHne-Jet-Spreading simulates the full near field region, considering special
features on inclined dense jets and the flow behavior along the spreading layer
(intermediate field). Coupling conditions (2D) for a far field region model are
provided.
▪ BrIHne models can be online run from www.brihne.ihcantabria.com . (training
course: brihnesupport@ihcantabria.com )
▪ BrIHne models will be improved and updated as new experimental data are
developed (multiport jets with merging, direct surface discharge, far field
regions, etc.). CFD models are being implemented (but they must be calibrated
and validated with high quality experimental data)
BRIHNE-JET-SPREADING
Thank you very much for
your attention
palomarmp@unican.es
www.brihne.ihcantabria.com