open TELEMAC-MASCARET The mathematically superior suite of solvers

Dear friends
I simulated the confluence flow with a length of 2.8m, an upstream width of 0.3m and a downstream width of 0.4m.. The hydrodynamic parameters are: the upstream is 0.006m3/s and 0.009m3/s respectively, and the downstream water depth is 0.16m.
My hydrodynamic cas file is as follows:
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/ VERTICAL
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NUMBER OF HORIZONTAL LEVELS : 12 / default and minimum is 2, upward vertical direction
MESH TRANSFORMATION : 1 / 0-CALCOT (user defined) 1-SIGMA (default) 3-user defined
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/ BOUNDARY CONDITIONS
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/ Use Nikuradse roughness law - all others are not 3D compatible
LAW OF BOTTOM FRICTION : 5
FRICTION COEFFICIENT FOR THE BOTTOM : 0.005 / 3 times d90 according to van Rijn
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/ Liquid boundaries - avoid Thompson (invalid in 3d)
PRESCRIBED ELEVATIONS = 0;0;0.22
PRESCRIBED FLOWRATES = 0.006;0.009;0
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/ INITIAL CONDITIONS
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INITIAL CONDITIONS : 'CONSTANT ELEVATION' / or CONSTANT DEPTH see docs sec. 4.2
INITIAL ELEVATION : 0.22 / corresponds to depth here - not in boundary file
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/ Other
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/ VELOCITY VERTICAL PROFILES : 2;2 / 0 (user-defined), 1 (Constant), 2 (Log)
/ VELOCITY PROFILES : 1;1;1 / horizontal profile
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/ TIDAL FLATS
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TIDAL FLATS : YES
OPTION FOR THE TREATMENT OF TIDAL FLATS : 1
TREATMENT OF NEGATIVE DEPTHS : 2
/ more in section docs 6.6
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/ TURBULENCE
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/ in 3d use k-epsilon model, alternatively Spalart-Allmaras (5) or
/ Smagorinsky (4) for highly non-linear flow
HORIZONTAL TURBULENCE MODEL : 5
COEFFICIENT FOR HORIZONTAL DIFFUSION OF VELOCITIES : 0.001 / is default
VERTICAL TURBULENCE MODEL : 5
COEFFICIENT FOR VERTICAL DIFFUSION OF VELOCITIES : 0.0001 / is default
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/ NUMERICAL PARAMETERS
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/ ADVECTION-DIFFUSION
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SCHEME FOR ADVECTION OF VELOCITIES : 1
SCHEME FOR ADVECTION OF K-EPSILON : 1
/ MATRIX STORAGE : 3 / 1 (element-by-element), 3 (segment-wise faster)
/ SUPG OPTION : 0;0 / classic supg for U and V see docs sec 6.2.2
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/ PROPAGATION HEIGHT AND STABILITY
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IMPLICITATION FOR DEPTH : 0.51 / should be between 0.55 and 0.6
IMPLICITATION FOR VELOCITIES : 0.51 / should be between 0.55 and 0.6
IMPLICITATION FOR DIFFUSION : 0.51
IMPLICITATION FOR VELOCITIES = 1.
OPTION OF SOLVER FOR PROPAGATION = 3
OPTION OF SOLVER FOR DIFFUSION OF VELOCITIES = 3
FREE SURFACE GRADIENT COMPATIBILITY : 0.75 / default 1.
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/ MASS LUMPING - enable to fasten calculations (smoothens) - possibly avoid in 3d
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/ MASS-LUMPING FOR DIFFUSION : 1 / 1 is ON - 0 is OFF (default)
MASS-LUMPING FOR DEPTH : 1. / VELOCITY has no effect
/ MASS-LUMPING FOR WEAK CHARACTERISTICS : 1
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/ HYDRODYNAMICS
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/ HYDRODYNAMIC SOLVER
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NON-HYDROSTATIC VERSION : YES
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/ Solver ACCURACY&/ Solver MAXIMUM ITERATIONS
MAXIMUM NUMBER OF ITERATIONS FOR PPE = 400
MAXIMUM NUMBER OF ITERATIONS FOR PROPAGATION = 800
MAXIMUM NUMBER OF ITERATIONS FOR DIFFUSION OF VELOCITIES = 800
MAXIMUM NUMBER OF ITERATIONS FOR DIFFUSION OF K-EPSILON = 800
ACCURACY FOR PPE = 1.E-4
ACCURACY FOR DIFFUSION OF VELOCITIES = 1.E-4
ACCURACY FOR PROPAGATION = 1.E-4
ACCURACY FOR DIFFUSION OF K-EPSILON = 1.E-6
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SOLVER FOR PROPAGATION = 7
SOLVER FOR DIFFUSION OF VELOCITIES = 7
MASS-BALANCE : YES
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PRECONDITIONING FOR DIFFUSION OF VELOCITIES : 0
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In this simulation process, I tried five turbulence models and different turbulence models corresponding to different convection schemes.
TURBULENCE MODEL ：1
TURBULENCE MODEL ：2
TURBULENCE MODEL ：3
TURBULENCE MODEL ：4
TURBULENCE MODEL ：5
TURBULENCE MODEL ：9
Advection scheme
SCHEME FOR ADVECTION OF VELOCITIES : 1
SCHEME FOR ADVECTION OF K-EPSILON : 1
SCHEME FOR ADVECTION OF VELOCITIES : 2
SCHEME FOR ADVECTION OF K-EPSILON : 2
SCHEME FOR ADVECTION OF VELOCITIES : 3
SCHEME FOR ADVECTION OF K-EPSILON : 3
SCHEME FOR ADVECTION OF VELOCITIES : 4
SCHEME FOR ADVECTION OF K-EPSILON : 4
SCHEME FOR ADVECTION OF VELOCITIES : 5
SCHEME FOR ADVECTION OF K-EPSILON : 5
SCHEME FOR ADVECTION OF VELOCITIES : 13
SCHEME FOR ADVECTION OF K-EPSILON : 13
SCHEME FOR ADVECTION OF VELOCITIES : 14
SCHEME FOR ADVECTION OF K-EPSILON : 14
Even through my attempt, I still can't simulate the results that are close to the experimental results. I have read the manual many times and tried different turbulence models and advection schemes. In this case, how should I modify my model in the future?
Best wishes
Abandoned

What are your results?
What are the experiments measurements.
Are the discharge ok in your model? Steady state reached?
Before playing with turbulence, maybe you should try to tune the friction...
hope this helps

Hello c.coulet,
Thank you for your answer. In this process, my simulation results are as shown in the figure, and the longitudinal velocity of the measuring points is compared. As can be seen from the figure, there is a big gap between the results of physical model test and the results of numerical simulation. The stability analysis is also carried out, and the model is stable. I adjusted the roughness, and now I have rebuilt the model. This is my new cas file:
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INITIAL CONDITIONS : 'CONSTANT DEPTH'
INITIAL DEPTH : 0.16
PRESCRIBED FLOWRATES : 0.006;0.009;0
/
/
PRESCRIBED ELEVATIONS : 0;0.;0.22
/LOGARITHMIC PROFILE
VELOCITY VERTICAL PROFILES = 2;2;2
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TIDAL FLATS = NO
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VARIABLES FOR 2D GRAPHIC PRINTOUTS = U,V,H,B,S
VARIABLES FOR 3D GRAPHIC PRINTOUTS = Z,U,V,W,RI,NUZ,TA1,NAZ1,EPS,K
MASS-BALANCE = YES
NON-HYDROSTATIC VERSION = YES
PRANDTL NUMBER = 0.71
KARMAN CONSTANT = 0.41
/

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/ CONVECTION-DIFFUSION
/

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SCHEME FOR ADVECTION OF VELOCITIES : 4
SCHEME FOR ADVECTION OF TRACERS : 4
SCHEME FOR ADVECTION OF K-EPSILON : 4
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/ K-EPSILON
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HORIZONTAL TURBULENCE MODEL = 3
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/ Viscosite constante
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/ HORIZONTAL TURBULENCE MODEL = 1
/ COEFFICIENT FOR HORIZONTAL DIFFUSION OF VELOCITIES = 5.D-3
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/ K-EPSILON
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VERTICAL TURBULENCE MODEL = 3
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/ MIXING LENGTH + PRANDTL + VIOLLET
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/ VERTICAL TURBULENCE MODEL = 2
/ MIXING LENGTH MODEL = 1
/ DAMPING FUNCTION = 2
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/ TERMES SOURCES
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FRICTION COEFFICIENT FOR THE BOTTOM = 63.4505
TURBULENCE REGIME FOR THE BOTTOM = 1 / LISSE
LAW OF BOTTOM FRICTION = 1 / HAALAND
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/ PROPAGATION
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MAXIMUM NUMBER OF ITERATIONS FOR PPE = 400
MAXIMUM NUMBER OF ITERATIONS FOR PROPAGATION = 1600
MAXIMUM NUMBER OF ITERATIONS FOR DIFFUSION OF VELOCITIES = 1600
MAXIMUM NUMBER OF ITERATIONS FOR DIFFUSION OF K-EPSILON = 1600
ACCURACY FOR DIFFUSION OF VELOCITIES = 1.E-4
ACCURACY FOR DIFFUSION OF K-EPSILON = 1.E-4
ACCURACY FOR DIFFUSION OF TRACERS = 1.E-4
ACCURACY FOR PROPAGATION = 1.E-4
ACCURACY FOR PPE = 1.E-4
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IMPLICITATION FOR DEPTH = 1.
/

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/ SEDIMENT
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/ NO FRICTION
LAW OF FRICTION ON LATERAL BOUNDARIES : 0
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IMPLICITATION FOR DIFFUSION : 2.
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/ DEFAULT VALUES UNTIL V8P0 KEPT FOR NON REGRESSION
SCHEME OPTION FOR ADVECTION OF VELOCITIES = 1
IMPLICITATION FOR VELOCITIES = 1.
SCHEME OPTION FOR ADVECTION OF TRACERS = 1
SCHEME OPTION FOR ADVECTION OF K-EPSILON = 1

The following error occurred when running this new cas file:
ITERATION 400 TIME 0 D 0 H 0 MN 1.0000 S ( 1.0000 S)
================================================================================

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ADVECTION STEP
MURD3D OPTION: 4 1 ITERATIONS
MURD3D OPTION: 4 1 ITERATIONS
MURD3D OPTION: 4 1 ITERATIONS
DIFFUSION OF WN
GRACJG (BIEF) : 1 ITERATIONS, ABSOLUTE PRECISION: 0.2634724E-06

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PROPAGATION AND DIFFUSION WITH WAVE EQUATION
GMRES (BIEF) : 1 ITERATIONS, ABSOLUTE PRECISION: 0.2203300E-08

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DYNAMIC PRESSURE STAGE
GMRES (BIEF) : 1 ITERATIONS, ABSOLUTE PRECISION: 0.3540126E-04

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VELOCITY PROJECTION STEP

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ADVECTION-DIFFUSION OF K-EPSILON OR OMEGA STEP
MURD3D OPTION: 4 1 ITERATIONS
DIFFUSION OF AKN
GRACJG (BIEF) : 0 ITERATIONS, ABSOLUTE PRECISION: 0.5969664E-06
MURD3D OPTION: 4 1 ITERATIONS
DIFFUSION OF EPN
GRACJG (BIEF) : 0 ITERATIONS, ABSOLUTE PRECISION: 0.9702098E-04

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MASS BALANCE

WATER
VOLUME AT THE PREVIOUS TIME STEP : 0.2202897
VOLUME AT THE PRESENT TIME STEP : 0.2203351
VOLUME LEAVING DOMAIN DURING THIS TIME STEP : -0.4542840E-04
ERROR ON THE VOLUME DURING THIS TIME STEP : -0.6279446E-11
BOUNDARY FLUXES FOR WATER IN M3/S ( >0 : ENTERING )
FLUX BOUNDARY 1 : 0.6000000E-02
FLUX BOUNDARY 2 : 0.9000000E-02
FLUX BOUNDARY 3 : 0.3171362E-02

job aborted:
[ranks] message

[0-7] terminated

[8] application aborted
aborting MPI_COMM_WORLD (comm=0x44000000), error 2, comm rank 8

[9-11] terminated

---- error analysis

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[8] on CHINAMI-IHM506L
C:\TELEMAC\V8P4\LT\model\model_yuan\HYDRO_bottom\90\mesh\heshidecasfangan\001mesh\3_2\ly15\viollet\t3d_viollet.cas_2025-02-18-01h50min39s\out_telemac3d.exe aborted the job. abort code 2

---- error analysis

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Traceback (most recent call last):
File "C:\TELEMAC\V8P4\scripts\python3\telemac3d.py", line 7, in <module>
main('telemac3d')
File "C:\TELEMAC\V8P4\scripts\python3\runcode.py", line 288, in main
run_study(cas_file, code_name, options)
File "C:\TELEMAC\V8P4\scripts\python3\execution\run_cas.py", line 169, in run_study
run_local_cas(my_study, options)
File "C:\TELEMAC\V8P4\scripts\python3\execution\run_cas.py", line 65, in run_local_cas
my_study.run(options)
File "C:\TELEMAC\V8P4\scripts\python3\execution\study.py", line 644, in run
self.run_local()
File "C:\TELEMAC\V8P4\scripts\python3\execution\study.py", line 465, in run_local
run_code(self.run_cmd, self.sortie_file)
File "C:\TELEMAC\V8P4\scripts\python3\execution\run.py", line 182, in run_code
raise TelemacException('Fail to run\n'+exe)
utils.exceptions.TelemacException: Fail to run
mpiexec -n 12 C:\TELEMAC\V8P4\LT\model\model_yuan\HYDRO_bottom\90\mesh\heshidecasfangan\001mesh\3_2\ly15\viollet\t3d_viollet.cas_2025-02-18-01h50min39s\out_telemac3d.exe
I referred to the manual, but I don't know how to modify the model. How can I modify the model? Thank you for taking the time to answer my questions. Attached are my cas file and Fortran file.
Best wishes
Abandoned

Just looking at the log file, 3 boundaries all with positive discharge means there is 3 entry of water (then also downstream)...

Hello c.coulet,
Thank you for your answer. As shown in the log file, all three are inflow. In the cas file and the boundary file cli, I defined that boundary 3 is outflow and water level boundary 544. The log file only shows the simulation of one time step, and the next simulation cannot be carried out. I can understand that there are three inflow boundaries because my initial water level is set too high. Or other reasons? Can you give me some suggestions for modification?
Best wishes
Abandoned

Try to build your steering file step by step...
Start with only the basics: initial condition, boundary condition, friction and try to run the simulation.
I don't think fortran file is needed at this step.
When this simple case works, upgrade the model by adding turbulence.

Regards

Hello,

Christophe is right, build step by step and use more complex options step by step.

I would also add, start with default values and always think why you change them.
Looking at your listing file, only 1 iteration (or no iteration) is used to solve the different linear systems, with quite coarse accuracy (e.g. 1.E-4). That means you do not really converge for these linear systems (and your solutions are suspicious).

Hope this helps,

Chi-Tuan