[va-ta-cfd]

Dear All,
Hi,

I am trying to use sediment transport function of Reef3D. My question is about "S 73" command that applies relaxation on the sediment bed. Can anyone explain what is the value (first double input) and the line angle (third double input) mentioned in the manual for "S 73"?

Best Regards,
Vahid

[valgrinda]

S 73 helps to fix the bed in inflow and outflow conditions, where otherwise you might experience unnatural or unwanted erosion.

The first value: the z-coordinate to which you want to relax the bed elevation to.

angle: the relaxation method is based around an imaginary line, so the angle would rotate it. I guess it is not so important for you.

[va-ta-cfd]

I got it. Thank you Dr. Bihs.

One more question.
The sediment function works well for flat beds. Simply by using S 57 command, we can specify the sediment end in z-direction for whole domain.

The question is how the Reef3D models the inclined bed sedimentation?

I tested both “grid option in DivMesh (G 10, G 11, and G 15)” or “wedge Topo ini (G 61 command)”. As soon as I add the sloped bed to the model, the results get weird with sharp fluctuations on the bed.

I know that you are currently improving sediment function of Reef3D, but it would be great if you could provide me some tips so I can move a step forward.

Best Regards,
Vahid

[valgrinda]

For more complex initial sediment beds, I recommend the geo.dat options for the bed topography interpolation. This will be the starting point of the sediment bed. Then you are totally free to define any bed geometry. For easier geometries you could use the G 60 and G 61 options (in REEF3D). G 61 would probably do what you ask for, as it can describe a sloping bed (in x-direction).

[va-ta-cfd]

Originally Posted by valgrinda

For more complex initial sediment beds, I recommend the geo.dat options for the bed topography interpolation. This will be the starting point of the sediment bed. Then you are totally free to define any bed geometry. For easier geometries you could use the G 60 and G 61 options (in REEF3D). G 61 would probably do what you ask for, as it can describe a sloping bed (in x-direction).

Many thanks for your quick reply.
I have done the same. But I get weird results as attached.
Do you have any tips for more smooth bed deformations?
Your guidance are quite valuable for me.