open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello,

I'm tying to model sediment inflow over a non erdodable bottom with T2D and Sisyphe. The whole domain is non erodable. So the model should deposit only sediment from the inflow and eventually pick up it again.

When comparing the -sum of the cumulated evolution- in the log file with the prescribed total volume which entered into the domain during the simulation, I noticed that they differ a lot. The -sum of the cumulated evolution- is nearly two times greater than the prescribed inflow volume. Where dows the sediment come from?

Very thanks for any advice!
Clemens

Porosity.

The masses should be the same, the influx volume is larger then the bed volume which contains pores. With default settig the ratio will be 1:1.66

Thank you! This makes sense.

I'm still struggeling how Sisyphe deals with a non erodable bed.
In the result file I have bed load transport where there is no sediment to erode. In this case the bed load discharge in the result file is the potential transport capacity and so it doesn't matter?
This maybe could explain also the final log file output?

VOLUME THAT ENTERED THE DOMAIN : -12139.47 M3 ( IF <0 EXIT )

The total inflow volume was around 4000 m3.

Clemens

To clarify my question or my assumption:

If Sisysphe computes over an non erodable bed a virtual bed load transport capacity e.g. according to MPM, then maybe there is not enough transport capacity anymore to transport the sediment coming from upstream?

Clemens

In principle, the transport rates are reduced if the amount of sediment available on the bed is less then the trasnport capacity.

Did you turn suspended sediments off? The total volume of the sediment entering is the sum of the bedload and the suspended load. It has nothing to do with bedload in the domain.

However, you say that the bedload is non-zero in areas without deposits.Is there any chance that the sediment passes through the domain within the output time steps?

Sorry I can't help you much here. The only advice I can give you is to compare the sediment amounts in kg's.

Michiel