[paulathikalam]

Hii all,

Could you help me out in calculating wave runup.

I had used P 52 as suggested in Wave runup, but i am confused in taking which value as for runup.

I am trying to find the wave runup on a slope.

Here is the control file:

C 11 6
C 12 3
C 13 3
C 14 21
C 15 21
C 16 3
B 1 0.025
B 10 0.0 21.0 0.0 0.025 0.0 1.4
S 61 5.0 15.0 0.0 0.025 0.0 1.0
S 10 15.0 21.0 0.0 0.025 0.0 1.0
S 61 15.0 21.0 0.0 0.025 1.0 1.10
M 10 8

here in which I am placing a water level of 1.05 and forcing a wave of 0.07 height. Tell me if there is a problem in doing this.

ctrl file:

B 10 1
B 50 0.0001
B 90 1
B 92 3
B 93 0.07 1.20
B 98 3
B 99 0
D 10 4
D 20 2
D 30 1
F 30 3
F 40 3
F 60 1.05
I 12 1
N 10 14
N 11 11
N 40 3
N 41 60.0
N 47 0.3
M 10 8
P 10 1
P 30 0.5
W 22 -9.81

T 10 2
T 10 2
T 31 0.816
T 32 0.212
T 36 2

P 40 1
P 52 0.0125
P 53 1
P 54 10

P 50 4.0 0.0125
P 50 5.5 0.0125
P 50 7.5 0.0125
P 50 15.0 0.0125
P 50 17.5 0.0125
P 50 19.5 0.0125
P 50 20.5 0.0125

P 51 4.0 0.0125
P 51 5.5 0.0125
P 51 7.5 0.0125
P 51 15.0 0.0125
P 51 17.5 0.0125
P 51 19.5 0.0125
P 51 20.5 0.0125

For runup- i could see files starting from REEF3D-CFD-wsfline-000000 to REEF3D-CFD-wsfline-008270; containing X1, P1,W1 -- is this the file in which we read wave run-up ?

Moreover, i could see a sharp shift in free surface line ( used contour - phi and also evident from the REEF3D-CFD-wsfline-000000; REEF3D-CFD-wsfline-008270 files) after some steps, is this normal ?? forgive my of ignorance if i had made errors or not known enough stuff .

Thanks

Paul

[kamath]

Hi Paul,

There is no direct ouptfile from REEF3D where you can read off the run up values.

P 52 is a wsfline output- i.e.- the free surface elevations over the x-direction at every selected time step (using P 54/55) is printed out.


To evaluate the wave run up, you will have to think of a post-processing method

The P 52 output is: X1 is the x-location and P1 the corresponding free surface elevation at probe P1. W1 is activated using P 53 1 and adds a column of free surface elevation calculated by wave theory, which is not relevant in your case.

Setting up a post-processing algorithm for these files in, say, Matlab can give you the run up distance.

-----
About your setup in particular:
Your tank height is 1.4 m, the SWL is 1.05 m, with wave crest ~1.2 m is filled with water. I would not recommend this. For this input, zmax should be around 2 m.

N 47 0.3 should be ok, but I have generally preferred to use 0.1. If your validation study shows 0.3 to be ok and the REEF3D is not crashing, should be ok.

I did not understand what you mean by this: "Moreover, i could see a sharp shift in free surface line".


You might want to explore using grid stretching to provide finer grids in the region of run up. (DIVEMesh B 101/103).

Hope that helps

[paulathikalam]

Dear Dr.Arun,

Thanks for the help.

i have changed the dimensions and grid as you suggested;

B 1 0.025
B 10 0.0 21.0 0.0 0.025 0.0 2.0
B 101 8
B 121 200 5 450 14 700
B 102 0
B 103 8
B 123 28 0.7 70 1.4 24

grid.png


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##### I did not understand what you mean by this: "Moreover, i could see a sharp shift in free surface line". ####

What i meant earlier; was when i plotted the free surface profile in paraview, you could see waterline upto 17.7m ( this is the updated simulation with finer mesh)

slope.png


after some time steps, the waterline drops to some extend down and oscillates up and down from there ( in the current simulation, this shift has considerably reduced (now its around 16.8m); may be it was the problem of the mesh that i had used earlier).


slope1.png


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Merry Christmas guys