open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi,

I'm interested to know where anybody has attempted to model the influence of silt curtains/screens which are partially suspended over the water column on SSC. I'm aware that some other models such as MIKE offer this functionality, however, I'm not entirely sure of the implementation.

A simplified approach I though could work would be using sink terms to remove SSC as a fraction of the current suspended sediment concentration (for instance by adopting a certain efficiency). Obviously this would not consider the influence of the curtains on flow and sediments trapped by the curtain would be removed from the domain.

More frequently I'm being asked to investigate the influence of silt curtains during dredging programs in our models so would be interested to understand how others may have attempted this.

Regards,
Toby

Based on the the lack of feedback it seems that the majority of users have not required this functionality and/or it hasn't been a major limitation for them.

Although I don't have the FORTRAN knowledge to effectively implement it, It would be great to have functionality similar to that of DHI's PlumeCast system. More than happy to discuss it further with any of the developers that might be interested.

Regards,
Toby

Hi,

I don't know what PlumeCast does into detail and I did not model silt curtains myselt, but I did model vertical screens within the mesh by assigning head losses / drag at nodes.

In the latest application, it was in order to model a screen extending to half of the water column that should prevent lateral spreading of flow and temperature. It worked just fine.

This can be done in the source subroutine from telemac3d. Search on the forum, there are examples available (maybe 10+ years old). Jean-Michel Hervouet has posted several suggestions on this topic.

The inconvenient of this method is that if you want the curtain to block the sediment concentration, it will have to be treated with a very high drag which implies that the screen will be impermeable, hence affecting the currents significantly. But this is maybe an acceptable assumption in some cases. Some tests with different drag coefficients can maybe lead to a satisfactory set-up.

I guess it might also be possible to use the same idea but only to act on the tracer diffusion, not the velocity field. Would be interesting to hear is other users have done this!

Kind regards
PL