[John CFD Newb]

Hello all,
I am using the sediment scour model for simulating the flow and settling in a sedimentation tank. My problem is that the suspended sediment never becomes packed (I have specified only the diameter and density for each sediment species and the other settings left to default). If I define an initial packed sediment region (in meshing and geometry), packed sediment is formed. Can you please help me why this is happening?

[JBurnham]

Can you tell us what version of FLOW-3D you're using? The v11 scour/deposition model is more reliable than older versions. You need the v11.0.2 patch (or later) to address settling completely - before that bed wouldn't form if there was only one cell of suspended sediment at the bottom, there needed to be at least two cells in vertical direction with suspended sediment concentration. After the patch a single cell of suspended sediment can pack properly.

[John CFD Newb]

Originally Posted by JBurnham

Can you tell us what version of FLOW-3D you're using? The v11 scour/deposition model is more reliable than older versions. You need the v11.0.2 patch (or later) to address settling completely - before that bed wouldn't form if there was only one cell of suspended sediment at the bottom, there needed to be at least two cells in vertical direction with suspended sediment concentration. After the patch a single cell of suspended sediment can pack properly.

I am using v11.0.1.
Thank you very much for your quick answer. I have another question if you can help me. I have specified 6 different classes with different diameter. I have also set boundary conditions for them with different concentrations. After the simulation I try to find the efficiency of the tank for each sediment species. For some reason, the concentration of the sediment with a smaller diameter in(3rd class) is much smaller than in 4th compared to Cin. So the efficiency of the class with the smaller diameter is bigger.Why is this happening, I am thinking sth wrong?

[AliZuhaira]

Hello,
I just want to ask you about the average of the running time which you needed to simulate this problem???
Thanks in Advance

[John CFD Newb]

The running time depends on different parameters like the size of geometry, the mesh, the computing power of your machine, the finish time that you have selected as input variable.

[redvangh]

Hello dear,
I am a beginner user of FLOW3D and have a problem in my simulation. I want to model a reservoir with 58 meters depth with an outet(spillway) on the top of the dam bady. There is a river in the x(min) of the geometry flows into the reservoir. The inputs of the river and reservoirs are:

Suspended sediment concentration of Reservoir=0.0762 gr/l
Temperature of the reservoir's water=15 Centigrade degree
Initial depth of the reservoir=58 m
Suspended sediment diameter=0.0003 m

Suspended sediment concentration of River=0.00505 gr/l
Temperature of the reservoir's water=15 Centigrade degree
Suspended sediment diameter=0.0003 m
Discharge=25.128 cubic meter per second

but the results are not true i think. I am sending you figures of these results that shows the suspended sediment concentration in the first time frames.

Could you please help me to find errors or mistakes.
Thank you very much.

Best regards,

[redvangh]

here are the first frames that show the problems.