open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi, everyone,

I am confused with the initial condition of TELEMAC2D, for my river case, I know the inflow of upstream is 700m3/s, the water surface elevation of downstream is 0.4m, which is the mouth of the sea. and the watershed is a very big, the difference between the upstream and downstream varies much. How can I set the initial conditions for my case?

I checked the telemac2d manual, which can set the initial conditions through 5 possible choices by the keyword " INITIAL CONDITIONS", they are separately,
"ZERO ELEVATION"
"CONSTANT ELEVATION"
"ZERO DEPTH"
"CONSTANT DEPTH"
"PARTICULAR"

which condition should I use for my case? any suggestions will be appreciated!

Best regards!
yajuan

Hi
JM Hervouet already gives you some advices on the different possibility you have. It's not necessary to duplicate the topics!!!

As already wrote, in a case where there is a big variation between upstream and downstream, the best solution is to manually build an initial water level.
You could do that manually by programming it in fortran --> "PARTICULAR" or try to build this initial water level in Fudaa or Blue Kenue and save it in a selafin format in order to use it as a previous computational file.

In fudaa, the idea is to build a line of the water level along the river (with some information about the water level elevation) and the fudaa automaticaly compute cross sections and generate the initial free surface. It could also compute an approxiamtion of velocity if you give the discharge.
In Kenue, the idea is quite similar, using points, profil along the river or generate a plane which approximate the free surface and mapping it on the free surface variable of the mesh

Dear Coulet,

Thank you for your reply!

I have rerun the case, now I can get the positive volume in the domain and the flux boundary(upstream), maybe this time is correct finally, hope to get the correct water depth. the initial condition I am using is what JMH suggested, hope this time can success.

Best regards!
yajuan