[NTNHAN]

Hello everyone,

How to define erosion zone on slope bed under wave?

Thank you.

NTNHAN

[valgrinda]

Use the 'Topo' geometry options in DIVEMesh. These type of geometries are erodible (in contrast to solid).

[NTNHAN]

Dear Prof. Hans Bihs

I am trying to simulate the scouring of the sloping bed under the wave. Using S to create a sloping solid and T to create sloping bed as shown figure below.

I have a problem is that the water level decreasing according to time (maybe the elevation of the sloping bed change leading to the water level decreasing).

The function of S 73 can not activate the erosion zone on the sloping bed.?

I attached my input file below. Hope that the REEF3D team and everyone give me some comments to have a better simulation.

Thank you for considering, Prof.

NTNHAN

[Ronja]

Hi,


Thanks for your questions!



a) water level decreasing over time: did you discover a problem with mass conservation? Is the mean water level is decreasing over time? Can you confirm without sediment transport? Do you have a plot?



b) S 73: What is your goal with S 73 here? S 73 defines a relaxation zone, not the active zone.

What exactly is the problem here? No erosion/sediment transport occurring?
Be aware that with your setup, the sediment transport algorithm starts after 1000 iterations. Not 25.0 sec as you defined in S 45.



On another note:

- you might need a higher wave tank. your water level is 0.40 + wave height of 0.12 = 0.52. Your wave tank is 0.6 m in z-dimension. Simulating the wave tank only is without problems with 0.6 m? Make sure your wave tank is set up first (check wave simulation) and then include the sediment module.

- Is there a special reason you decided to have 5 cells in y-direction?



A small tip to be on the safe side: use a double if double is requested (e.g. S 81 40.0)

[valgrinda]

As Ronja mentioned, you need to you a tank with 0.8m height. Also: better to run this case in 2D, but higher resolution (dx =1cm),

Most important: using S 15 2 leads to too large sediment time steps and weird topo behavior. Just go with the default (S 15 0).

[NTNHAN]

Dear Prof. Hans Bihs, Ronja.

Thank you so much for your recommendations. I tried my best to fix my problem, but it was unsuccessful.

I have two problems:
1. The water level decreases significantly after the simulation of 3600 seconds of sediment transport time.
2. The shape of the wave generated at the inlet of NWT is not actual.

I have attached three figures below about my problem.

Please give me some comments to solve these problems.

Respectfully, thank you for your help.

Below are the control.txt and ctrl.txt I used in my simulation.

CONTROL FILE
C 11 6
C 12 3
C 13 3
C 14 7
C 15 21
C 16 3

B 1 0.015
B 10 0 15 0.0 0.015 0.0 0.8

S 61 5 7 0 0.015 0 0.1
S 10 7 7.15 0 0.015 0 0.23
T 84 7.15 0 0 15 0 0 15 0.015 0 7.15 0.015 0 7.15 0 0.108 15 0 0.5 15 0.015 0.5 7.15 0.015 0.108

M 20 2
M 10 24

CTRL FILE
B 10 1
B 50 0.001
B 90 1
B 92 8
B 93 0.139 1.33
B 96 0.0 0.0
B 98 3
B 99 4

D 10 4
D 20 2
D 30 1

F 10 2
F 30 3
F 35 5
F 40 23
F 42 1.0
F 50 2
F 60 0.35

I 12 1

N 10 14
N 11 11
N 40 3
N 47 0.2
N 48 1

M 10 24

S 10 1
S 11 1
S 12 1
S 13 0.65
S 14 0.3
S 15 0
S 16 1
S 19 3600
S 20 0.00058
S 21 3
S 22 2650
S 23 0.083
S 24 0.6
S 30 0.030
S 32 4
S 42 3
S 48 0.02
S 50 3
S 60 3
S 73 0 5 0 0 0
S 80 2
S 81 40
S 82 5
S 83 5
S 84 1
S 90 1
S 93 2

P 10 1
P 27 1
P 30 1
P 40 1
P 42 5
P 79 1
P 122 1
P 126 1
P 180 1
P 182 1

T 10 2
T 12 5
T 36 2

W 22 -9.81

[ajayjatoliya]

Hello everyone,

I have a query, how to chose S 13 and S 14 parameters ?

[NTNHAN]

Dear Professor Hans Bihs, REEF3D team and everyone

Please have a look and give me the solution (if possible) to my problem.

Thank you for your time and kind consideration!

NTNHAN

[valgrinda]

for example:
S 13 5.0
S 14 0.5

[NTNHAN]

Originally Posted by NTNHAN

Dear Prof. Hans Bihs, Ronja.

Thank you so much for your recommendations. I tried my best to fix my problem, but it was unsuccessful.

I have two problems:
1. The water level decreases significantly after the simulation of 3600 seconds of sediment transport time.
2. The shape of the wave generated at the inlet of NWT is not actual.

I have attached three figures below about my problem.

Please give me some comments to solve these problems.

Respectfully, thank you for your help.

Below are the control.txt and ctrl.txt I used in my simulation.

CONTROL FILE
C 11 6
C 12 3
C 13 3
C 14 7
C 15 21
C 16 3

B 1 0.015
B 10 0 15 0.0 0.015 0.0 0.8

S 61 5 7 0 0.015 0 0.1
S 10 7 7.15 0 0.015 0 0.23
T 84 7.15 0 0 15 0 0 15 0.015 0 7.15 0.015 0 7.15 0 0.108 15 0 0.5 15 0.015 0.5 7.15 0.015 0.108

M 20 2
M 10 24

CTRL FILE
B 10 1
B 50 0.001
B 90 1
B 92 8
B 93 0.139 1.33
B 96 0.0 0.0
B 98 3
B 99 4

D 10 4
D 20 2
D 30 1

F 10 2
F 30 3
F 35 5
F 40 23
F 42 1.0
F 50 2
F 60 0.35

I 12 1

N 10 14
N 11 11
N 40 3
N 47 0.2
N 48 1

M 10 24

S 10 1
S 11 1
S 12 1
S 13 0.65
S 14 0.3
S 15 0
S 16 1
S 19 3600
S 20 0.00058
S 21 3
S 22 2650
S 23 0.083
S 24 0.6
S 30 0.030
S 32 4
S 42 3
S 48 0.02
S 50 3
S 60 3
S 73 0 5 0 0 0
S 80 2
S 81 40
S 82 5
S 83 5
S 84 1
S 90 1
S 93 2

P 10 1
P 27 1
P 30 1
P 40 1
P 42 5
P 79 1
P 122 1
P 126 1
P 180 1
P 182 1

T 10 2
T 12 5
T 36 2

W 22 -9.81

Dear Professor Hans Bihs, REEF3D team and everyone

Here is my broblem

[valgrinda]

I would start just testing the waves and then go step by step.

[NTNHAN]

Dear Prof. Hans Bihs, and everyone.

Until now, I still have not solved this problem.

Please have a look, and give me recommendations to fix the problems.

Respectly thanks.

NTNHAN